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Diffstat (limited to 'third_party/git/merge-recursive.c')
| -rw-r--r-- | third_party/git/merge-recursive.c | 3760 |
1 files changed, 3760 insertions, 0 deletions
diff --git a/third_party/git/merge-recursive.c b/third_party/git/merge-recursive.c new file mode 100644 index 000000000000..6b812d67e3ec --- /dev/null +++ b/third_party/git/merge-recursive.c @@ -0,0 +1,3760 @@ +/* + * Recursive Merge algorithm stolen from git-merge-recursive.py by + * Fredrik Kuivinen. + * The thieves were Alex Riesen and Johannes Schindelin, in June/July 2006 + */ +#include "cache.h" +#include "config.h" +#include "advice.h" +#include "lockfile.h" +#include "cache-tree.h" +#include "object-store.h" +#include "repository.h" +#include "commit.h" +#include "blob.h" +#include "builtin.h" +#include "tree-walk.h" +#include "diff.h" +#include "diffcore.h" +#include "tag.h" +#include "alloc.h" +#include "unpack-trees.h" +#include "string-list.h" +#include "xdiff-interface.h" +#include "ll-merge.h" +#include "attr.h" +#include "merge-recursive.h" +#include "dir.h" +#include "submodule.h" +#include "revision.h" +#include "commit-reach.h" + +struct path_hashmap_entry { + struct hashmap_entry e; + char path[FLEX_ARRAY]; +}; + +static int path_hashmap_cmp(const void *cmp_data, + const void *entry, + const void *entry_or_key, + const void *keydata) +{ + const struct path_hashmap_entry *a = entry; + const struct path_hashmap_entry *b = entry_or_key; + const char *key = keydata; + + if (ignore_case) + return strcasecmp(a->path, key ? key : b->path); + else + return strcmp(a->path, key ? key : b->path); +} + +static unsigned int path_hash(const char *path) +{ + return ignore_case ? strihash(path) : strhash(path); +} + +static struct dir_rename_entry *dir_rename_find_entry(struct hashmap *hashmap, + char *dir) +{ + struct dir_rename_entry key; + + if (dir == NULL) + return NULL; + hashmap_entry_init(&key, strhash(dir)); + key.dir = dir; + return hashmap_get(hashmap, &key, NULL); +} + +static int dir_rename_cmp(const void *unused_cmp_data, + const void *entry, + const void *entry_or_key, + const void *unused_keydata) +{ + const struct dir_rename_entry *e1 = entry; + const struct dir_rename_entry *e2 = entry_or_key; + + return strcmp(e1->dir, e2->dir); +} + +static void dir_rename_init(struct hashmap *map) +{ + hashmap_init(map, dir_rename_cmp, NULL, 0); +} + +static void dir_rename_entry_init(struct dir_rename_entry *entry, + char *directory) +{ + hashmap_entry_init(entry, strhash(directory)); + entry->dir = directory; + entry->non_unique_new_dir = 0; + strbuf_init(&entry->new_dir, 0); + string_list_init(&entry->possible_new_dirs, 0); +} + +static struct collision_entry *collision_find_entry(struct hashmap *hashmap, + char *target_file) +{ + struct collision_entry key; + + hashmap_entry_init(&key, strhash(target_file)); + key.target_file = target_file; + return hashmap_get(hashmap, &key, NULL); +} + +static int collision_cmp(void *unused_cmp_data, + const struct collision_entry *e1, + const struct collision_entry *e2, + const void *unused_keydata) +{ + return strcmp(e1->target_file, e2->target_file); +} + +static void collision_init(struct hashmap *map) +{ + hashmap_init(map, (hashmap_cmp_fn) collision_cmp, NULL, 0); +} + +static void flush_output(struct merge_options *opt) +{ + if (opt->buffer_output < 2 && opt->obuf.len) { + fputs(opt->obuf.buf, stdout); + strbuf_reset(&opt->obuf); + } +} + +static int err(struct merge_options *opt, const char *err, ...) +{ + va_list params; + + if (opt->buffer_output < 2) + flush_output(opt); + else { + strbuf_complete(&opt->obuf, '\n'); + strbuf_addstr(&opt->obuf, "error: "); + } + va_start(params, err); + strbuf_vaddf(&opt->obuf, err, params); + va_end(params); + if (opt->buffer_output > 1) + strbuf_addch(&opt->obuf, '\n'); + else { + error("%s", opt->obuf.buf); + strbuf_reset(&opt->obuf); + } + + return -1; +} + +static struct tree *shift_tree_object(struct repository *repo, + struct tree *one, struct tree *two, + const char *subtree_shift) +{ + struct object_id shifted; + + if (!*subtree_shift) { + shift_tree(repo, &one->object.oid, &two->object.oid, &shifted, 0); + } else { + shift_tree_by(repo, &one->object.oid, &two->object.oid, &shifted, + subtree_shift); + } + if (oideq(&two->object.oid, &shifted)) + return two; + return lookup_tree(repo, &shifted); +} + +static inline void set_commit_tree(struct commit *c, struct tree *t) +{ + c->maybe_tree = t; +} + +static struct commit *make_virtual_commit(struct repository *repo, + struct tree *tree, + const char *comment) +{ + struct commit *commit = alloc_commit_node(repo); + + set_merge_remote_desc(commit, comment, (struct object *)commit); + set_commit_tree(commit, tree); + commit->object.parsed = 1; + return commit; +} + +/* + * Since we use get_tree_entry(), which does not put the read object into + * the object pool, we cannot rely on a == b. + */ +static int oid_eq(const struct object_id *a, const struct object_id *b) +{ + if (!a && !b) + return 2; + return a && b && oideq(a, b); +} + +enum rename_type { + RENAME_NORMAL = 0, + RENAME_VIA_DIR, + RENAME_ADD, + RENAME_DELETE, + RENAME_ONE_FILE_TO_ONE, + RENAME_ONE_FILE_TO_TWO, + RENAME_TWO_FILES_TO_ONE +}; + +/* + * Since we want to write the index eventually, we cannot reuse the index + * for these (temporary) data. + */ +struct stage_data { + struct diff_filespec stages[4]; /* mostly for oid & mode; maybe path */ + struct rename_conflict_info *rename_conflict_info; + unsigned processed:1; +}; + +struct rename { + unsigned processed:1; + struct diff_filepair *pair; + const char *branch; /* branch that the rename occurred on */ + /* + * If directory rename detection affected this rename, what was its + * original type ('A' or 'R') and it's original destination before + * the directory rename (otherwise, '\0' and NULL for these two vars). + */ + char dir_rename_original_type; + char *dir_rename_original_dest; + /* + * Purpose of src_entry and dst_entry: + * + * If 'before' is renamed to 'after' then src_entry will contain + * the versions of 'before' from the merge_base, HEAD, and MERGE in + * stages 1, 2, and 3; dst_entry will contain the respective + * versions of 'after' in corresponding locations. Thus, we have a + * total of six modes and oids, though some will be null. (Stage 0 + * is ignored; we're interested in handling conflicts.) + * + * Since we don't turn on break-rewrites by default, neither + * src_entry nor dst_entry can have all three of their stages have + * non-null oids, meaning at most four of the six will be non-null. + * Also, since this is a rename, both src_entry and dst_entry will + * have at least one non-null oid, meaning at least two will be + * non-null. Of the six oids, a typical rename will have three be + * non-null. Only two implies a rename/delete, and four implies a + * rename/add. + */ + struct stage_data *src_entry; + struct stage_data *dst_entry; +}; + +struct rename_conflict_info { + enum rename_type rename_type; + struct rename *ren1; + struct rename *ren2; +}; + +static inline void setup_rename_conflict_info(enum rename_type rename_type, + struct merge_options *opt, + struct rename *ren1, + struct rename *ren2) +{ + struct rename_conflict_info *ci; + + /* + * When we have two renames involved, it's easiest to get the + * correct things into stage 2 and 3, and to make sure that the + * content merge puts HEAD before the other branch if we just + * ensure that branch1 == opt->branch1. So, simply flip arguments + * around if we don't have that. + */ + if (ren2 && ren1->branch != opt->branch1) { + setup_rename_conflict_info(rename_type, opt, ren2, ren1); + return; + } + + ci = xcalloc(1, sizeof(struct rename_conflict_info)); + ci->rename_type = rename_type; + ci->ren1 = ren1; + ci->ren2 = ren2; + + ci->ren1->dst_entry->processed = 0; + ci->ren1->dst_entry->rename_conflict_info = ci; + if (ren2) { + ci->ren2->dst_entry->rename_conflict_info = ci; + } +} + +static int show(struct merge_options *opt, int v) +{ + return (!opt->call_depth && opt->verbosity >= v) || opt->verbosity >= 5; +} + +__attribute__((format (printf, 3, 4))) +static void output(struct merge_options *opt, int v, const char *fmt, ...) +{ + va_list ap; + + if (!show(opt, v)) + return; + + strbuf_addchars(&opt->obuf, ' ', opt->call_depth * 2); + + va_start(ap, fmt); + strbuf_vaddf(&opt->obuf, fmt, ap); + va_end(ap); + + strbuf_addch(&opt->obuf, '\n'); + if (!opt->buffer_output) + flush_output(opt); +} + +static void output_commit_title(struct merge_options *opt, struct commit *commit) +{ + struct merge_remote_desc *desc; + + strbuf_addchars(&opt->obuf, ' ', opt->call_depth * 2); + desc = merge_remote_util(commit); + if (desc) + strbuf_addf(&opt->obuf, "virtual %s\n", desc->name); + else { + strbuf_add_unique_abbrev(&opt->obuf, &commit->object.oid, + DEFAULT_ABBREV); + strbuf_addch(&opt->obuf, ' '); + if (parse_commit(commit) != 0) + strbuf_addstr(&opt->obuf, _("(bad commit)\n")); + else { + const char *title; + const char *msg = get_commit_buffer(commit, NULL); + int len = find_commit_subject(msg, &title); + if (len) + strbuf_addf(&opt->obuf, "%.*s\n", len, title); + unuse_commit_buffer(commit, msg); + } + } + flush_output(opt); +} + +static int add_cacheinfo(struct merge_options *opt, + const struct diff_filespec *blob, + const char *path, int stage, int refresh, int options) +{ + struct index_state *istate = opt->repo->index; + struct cache_entry *ce; + int ret; + + ce = make_cache_entry(istate, blob->mode, &blob->oid, path, stage, 0); + if (!ce) + return err(opt, _("add_cacheinfo failed for path '%s'; merge aborting."), path); + + ret = add_index_entry(istate, ce, options); + if (refresh) { + struct cache_entry *nce; + + nce = refresh_cache_entry(istate, ce, + CE_MATCH_REFRESH | CE_MATCH_IGNORE_MISSING); + if (!nce) + return err(opt, _("add_cacheinfo failed to refresh for path '%s'; merge aborting."), path); + if (nce != ce) + ret = add_index_entry(istate, nce, options); + } + return ret; +} + +static void init_tree_desc_from_tree(struct tree_desc *desc, struct tree *tree) +{ + parse_tree(tree); + init_tree_desc(desc, tree->buffer, tree->size); +} + +static int unpack_trees_start(struct merge_options *opt, + struct tree *common, + struct tree *head, + struct tree *merge) +{ + int rc; + struct tree_desc t[3]; + struct index_state tmp_index = { NULL }; + + memset(&opt->unpack_opts, 0, sizeof(opt->unpack_opts)); + if (opt->call_depth) + opt->unpack_opts.index_only = 1; + else + opt->unpack_opts.update = 1; + opt->unpack_opts.merge = 1; + opt->unpack_opts.head_idx = 2; + opt->unpack_opts.fn = threeway_merge; + opt->unpack_opts.src_index = opt->repo->index; + opt->unpack_opts.dst_index = &tmp_index; + opt->unpack_opts.aggressive = !merge_detect_rename(opt); + setup_unpack_trees_porcelain(&opt->unpack_opts, "merge"); + + init_tree_desc_from_tree(t+0, common); + init_tree_desc_from_tree(t+1, head); + init_tree_desc_from_tree(t+2, merge); + + rc = unpack_trees(3, t, &opt->unpack_opts); + cache_tree_free(&opt->repo->index->cache_tree); + + /* + * Update opt->repo->index to match the new results, AFTER saving a copy + * in opt->orig_index. Update src_index to point to the saved copy. + * (verify_uptodate() checks src_index, and the original index is + * the one that had the necessary modification timestamps.) + */ + opt->orig_index = *opt->repo->index; + *opt->repo->index = tmp_index; + opt->unpack_opts.src_index = &opt->orig_index; + + return rc; +} + +static void unpack_trees_finish(struct merge_options *opt) +{ + discard_index(&opt->orig_index); + clear_unpack_trees_porcelain(&opt->unpack_opts); +} + +struct tree *write_tree_from_memory(struct merge_options *opt) +{ + struct tree *result = NULL; + struct index_state *istate = opt->repo->index; + + if (unmerged_index(istate)) { + int i; + fprintf(stderr, "BUG: There are unmerged index entries:\n"); + for (i = 0; i < istate->cache_nr; i++) { + const struct cache_entry *ce = istate->cache[i]; + if (ce_stage(ce)) + fprintf(stderr, "BUG: %d %.*s\n", ce_stage(ce), + (int)ce_namelen(ce), ce->name); + } + BUG("unmerged index entries in merge-recursive.c"); + } + + if (!istate->cache_tree) + istate->cache_tree = cache_tree(); + + if (!cache_tree_fully_valid(istate->cache_tree) && + cache_tree_update(istate, 0) < 0) { + err(opt, _("error building trees")); + return NULL; + } + + result = lookup_tree(opt->repo, &istate->cache_tree->oid); + + return result; +} + +static int save_files_dirs(const struct object_id *oid, + struct strbuf *base, const char *path, + unsigned int mode, int stage, void *context) +{ + struct path_hashmap_entry *entry; + int baselen = base->len; + struct merge_options *opt = context; + + strbuf_addstr(base, path); + + FLEX_ALLOC_MEM(entry, path, base->buf, base->len); + hashmap_entry_init(entry, path_hash(entry->path)); + hashmap_add(&opt->current_file_dir_set, entry); + + strbuf_setlen(base, baselen); + return (S_ISDIR(mode) ? READ_TREE_RECURSIVE : 0); +} + +static void get_files_dirs(struct merge_options *opt, struct tree *tree) +{ + struct pathspec match_all; + memset(&match_all, 0, sizeof(match_all)); + read_tree_recursive(opt->repo, tree, "", 0, 0, + &match_all, save_files_dirs, opt); +} + +static int get_tree_entry_if_blob(struct repository *r, + const struct object_id *tree, + const char *path, + struct diff_filespec *dfs) +{ + int ret; + + ret = get_tree_entry(r, tree, path, &dfs->oid, &dfs->mode); + if (S_ISDIR(dfs->mode)) { + oidcpy(&dfs->oid, &null_oid); + dfs->mode = 0; + } + return ret; +} + +/* + * Returns an index_entry instance which doesn't have to correspond to + * a real cache entry in Git's index. + */ +static struct stage_data *insert_stage_data(struct repository *r, + const char *path, + struct tree *o, struct tree *a, struct tree *b, + struct string_list *entries) +{ + struct string_list_item *item; + struct stage_data *e = xcalloc(1, sizeof(struct stage_data)); + get_tree_entry_if_blob(r, &o->object.oid, path, &e->stages[1]); + get_tree_entry_if_blob(r, &a->object.oid, path, &e->stages[2]); + get_tree_entry_if_blob(r, &b->object.oid, path, &e->stages[3]); + item = string_list_insert(entries, path); + item->util = e; + return e; +} + +/* + * Create a dictionary mapping file names to stage_data objects. The + * dictionary contains one entry for every path with a non-zero stage entry. + */ +static struct string_list *get_unmerged(struct index_state *istate) +{ + struct string_list *unmerged = xcalloc(1, sizeof(struct string_list)); + int i; + + unmerged->strdup_strings = 1; + + for (i = 0; i < istate->cache_nr; i++) { + struct string_list_item *item; + struct stage_data *e; + const struct cache_entry *ce = istate->cache[i]; + if (!ce_stage(ce)) + continue; + + item = string_list_lookup(unmerged, ce->name); + if (!item) { + item = string_list_insert(unmerged, ce->name); + item->util = xcalloc(1, sizeof(struct stage_data)); + } + e = item->util; + e->stages[ce_stage(ce)].mode = ce->ce_mode; + oidcpy(&e->stages[ce_stage(ce)].oid, &ce->oid); + } + + return unmerged; +} + +static int string_list_df_name_compare(const char *one, const char *two) +{ + int onelen = strlen(one); + int twolen = strlen(two); + /* + * Here we only care that entries for D/F conflicts are + * adjacent, in particular with the file of the D/F conflict + * appearing before files below the corresponding directory. + * The order of the rest of the list is irrelevant for us. + * + * To achieve this, we sort with df_name_compare and provide + * the mode S_IFDIR so that D/F conflicts will sort correctly. + * We use the mode S_IFDIR for everything else for simplicity, + * since in other cases any changes in their order due to + * sorting cause no problems for us. + */ + int cmp = df_name_compare(one, onelen, S_IFDIR, + two, twolen, S_IFDIR); + /* + * Now that 'foo' and 'foo/bar' compare equal, we have to make sure + * that 'foo' comes before 'foo/bar'. + */ + if (cmp) + return cmp; + return onelen - twolen; +} + +static void record_df_conflict_files(struct merge_options *opt, + struct string_list *entries) +{ + /* If there is a D/F conflict and the file for such a conflict + * currently exists in the working tree, we want to allow it to be + * removed to make room for the corresponding directory if needed. + * The files underneath the directories of such D/F conflicts will + * be processed before the corresponding file involved in the D/F + * conflict. If the D/F directory ends up being removed by the + * merge, then we won't have to touch the D/F file. If the D/F + * directory needs to be written to the working copy, then the D/F + * file will simply be removed (in make_room_for_path()) to make + * room for the necessary paths. Note that if both the directory + * and the file need to be present, then the D/F file will be + * reinstated with a new unique name at the time it is processed. + */ + struct string_list df_sorted_entries = STRING_LIST_INIT_NODUP; + const char *last_file = NULL; + int last_len = 0; + int i; + + /* + * If we're merging merge-bases, we don't want to bother with + * any working directory changes. + */ + if (opt->call_depth) + return; + + /* Ensure D/F conflicts are adjacent in the entries list. */ + for (i = 0; i < entries->nr; i++) { + struct string_list_item *next = &entries->items[i]; + string_list_append(&df_sorted_entries, next->string)->util = + next->util; + } + df_sorted_entries.cmp = string_list_df_name_compare; + string_list_sort(&df_sorted_entries); + + string_list_clear(&opt->df_conflict_file_set, 1); + for (i = 0; i < df_sorted_entries.nr; i++) { + const char *path = df_sorted_entries.items[i].string; + int len = strlen(path); + struct stage_data *e = df_sorted_entries.items[i].util; + + /* + * Check if last_file & path correspond to a D/F conflict; + * i.e. whether path is last_file+'/'+<something>. + * If so, record that it's okay to remove last_file to make + * room for path and friends if needed. + */ + if (last_file && + len > last_len && + memcmp(path, last_file, last_len) == 0 && + path[last_len] == '/') { + string_list_insert(&opt->df_conflict_file_set, last_file); + } + + /* + * Determine whether path could exist as a file in the + * working directory as a possible D/F conflict. This + * will only occur when it exists in stage 2 as a + * file. + */ + if (S_ISREG(e->stages[2].mode) || S_ISLNK(e->stages[2].mode)) { + last_file = path; + last_len = len; + } else { + last_file = NULL; + } + } + string_list_clear(&df_sorted_entries, 0); +} + +static int update_stages(struct merge_options *opt, const char *path, + const struct diff_filespec *o, + const struct diff_filespec *a, + const struct diff_filespec *b) +{ + + /* + * NOTE: It is usually a bad idea to call update_stages on a path + * before calling update_file on that same path, since it can + * sometimes lead to spurious "refusing to lose untracked file..." + * messages from update_file (via make_room_for path via + * would_lose_untracked). Instead, reverse the order of the calls + * (executing update_file first and then update_stages). + */ + int clear = 1; + int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_SKIP_DFCHECK; + if (clear) + if (remove_file_from_index(opt->repo->index, path)) + return -1; + if (o) + if (add_cacheinfo(opt, o, path, 1, 0, options)) + return -1; + if (a) + if (add_cacheinfo(opt, a, path, 2, 0, options)) + return -1; + if (b) + if (add_cacheinfo(opt, b, path, 3, 0, options)) + return -1; + return 0; +} + +static void update_entry(struct stage_data *entry, + struct diff_filespec *o, + struct diff_filespec *a, + struct diff_filespec *b) +{ + entry->processed = 0; + entry->stages[1].mode = o->mode; + entry->stages[2].mode = a->mode; + entry->stages[3].mode = b->mode; + oidcpy(&entry->stages[1].oid, &o->oid); + oidcpy(&entry->stages[2].oid, &a->oid); + oidcpy(&entry->stages[3].oid, &b->oid); +} + +static int remove_file(struct merge_options *opt, int clean, + const char *path, int no_wd) +{ + int update_cache = opt->call_depth || clean; + int update_working_directory = !opt->call_depth && !no_wd; + + if (update_cache) { + if (remove_file_from_index(opt->repo->index, path)) + return -1; + } + if (update_working_directory) { + if (ignore_case) { + struct cache_entry *ce; + ce = index_file_exists(opt->repo->index, path, strlen(path), + ignore_case); + if (ce && ce_stage(ce) == 0 && strcmp(path, ce->name)) + return 0; + } + if (remove_path(path)) + return -1; + } + return 0; +} + +/* add a string to a strbuf, but converting "/" to "_" */ +static void add_flattened_path(struct strbuf *out, const char *s) +{ + size_t i = out->len; + strbuf_addstr(out, s); + for (; i < out->len; i++) + if (out->buf[i] == '/') + out->buf[i] = '_'; +} + +static char *unique_path(struct merge_options *opt, const char *path, const char *branch) +{ + struct path_hashmap_entry *entry; + struct strbuf newpath = STRBUF_INIT; + int suffix = 0; + size_t base_len; + + strbuf_addf(&newpath, "%s~", path); + add_flattened_path(&newpath, branch); + + base_len = newpath.len; + while (hashmap_get_from_hash(&opt->current_file_dir_set, + path_hash(newpath.buf), newpath.buf) || + (!opt->call_depth && file_exists(newpath.buf))) { + strbuf_setlen(&newpath, base_len); + strbuf_addf(&newpath, "_%d", suffix++); + } + + FLEX_ALLOC_MEM(entry, path, newpath.buf, newpath.len); + hashmap_entry_init(entry, path_hash(entry->path)); + hashmap_add(&opt->current_file_dir_set, entry); + return strbuf_detach(&newpath, NULL); +} + +/** + * Check whether a directory in the index is in the way of an incoming + * file. Return 1 if so. If check_working_copy is non-zero, also + * check the working directory. If empty_ok is non-zero, also return + * 0 in the case where the working-tree dir exists but is empty. + */ +static int dir_in_way(struct index_state *istate, const char *path, + int check_working_copy, int empty_ok) +{ + int pos; + struct strbuf dirpath = STRBUF_INIT; + struct stat st; + + strbuf_addstr(&dirpath, path); + strbuf_addch(&dirpath, '/'); + + pos = index_name_pos(istate, dirpath.buf, dirpath.len); + + if (pos < 0) + pos = -1 - pos; + if (pos < istate->cache_nr && + !strncmp(dirpath.buf, istate->cache[pos]->name, dirpath.len)) { + strbuf_release(&dirpath); + return 1; + } + + strbuf_release(&dirpath); + return check_working_copy && !lstat(path, &st) && S_ISDIR(st.st_mode) && + !(empty_ok && is_empty_dir(path)); +} + +/* + * Returns whether path was tracked in the index before the merge started, + * and its oid and mode match the specified values + */ +static int was_tracked_and_matches(struct merge_options *opt, const char *path, + const struct diff_filespec *blob) +{ + int pos = index_name_pos(&opt->orig_index, path, strlen(path)); + struct cache_entry *ce; + + if (0 > pos) + /* we were not tracking this path before the merge */ + return 0; + + /* See if the file we were tracking before matches */ + ce = opt->orig_index.cache[pos]; + return (oid_eq(&ce->oid, &blob->oid) && ce->ce_mode == blob->mode); +} + +/* + * Returns whether path was tracked in the index before the merge started + */ +static int was_tracked(struct merge_options *opt, const char *path) +{ + int pos = index_name_pos(&opt->orig_index, path, strlen(path)); + + if (0 <= pos) + /* we were tracking this path before the merge */ + return 1; + + return 0; +} + +static int would_lose_untracked(struct merge_options *opt, const char *path) +{ + struct index_state *istate = opt->repo->index; + + /* + * This may look like it can be simplified to: + * return !was_tracked(opt, path) && file_exists(path) + * but it can't. This function needs to know whether path was in + * the working tree due to EITHER having been tracked in the index + * before the merge OR having been put into the working copy and + * index by unpack_trees(). Due to that either-or requirement, we + * check the current index instead of the original one. + * + * Note that we do not need to worry about merge-recursive itself + * updating the index after unpack_trees() and before calling this + * function, because we strictly require all code paths in + * merge-recursive to update the working tree first and the index + * second. Doing otherwise would break + * update_file()/would_lose_untracked(); see every comment in this + * file which mentions "update_stages". + */ + int pos = index_name_pos(istate, path, strlen(path)); + + if (pos < 0) + pos = -1 - pos; + while (pos < istate->cache_nr && + !strcmp(path, istate->cache[pos]->name)) { + /* + * If stage #0, it is definitely tracked. + * If it has stage #2 then it was tracked + * before this merge started. All other + * cases the path was not tracked. + */ + switch (ce_stage(istate->cache[pos])) { + case 0: + case 2: + return 0; + } + pos++; + } + return file_exists(path); +} + +static int was_dirty(struct merge_options *opt, const char *path) +{ + struct cache_entry *ce; + int dirty = 1; + + if (opt->call_depth || !was_tracked(opt, path)) + return !dirty; + + ce = index_file_exists(opt->unpack_opts.src_index, + path, strlen(path), ignore_case); + dirty = verify_uptodate(ce, &opt->unpack_opts) != 0; + return dirty; +} + +static int make_room_for_path(struct merge_options *opt, const char *path) +{ + int status, i; + const char *msg = _("failed to create path '%s'%s"); + + /* Unlink any D/F conflict files that are in the way */ + for (i = 0; i < opt->df_conflict_file_set.nr; i++) { + const char *df_path = opt->df_conflict_file_set.items[i].string; + size_t pathlen = strlen(path); + size_t df_pathlen = strlen(df_path); + if (df_pathlen < pathlen && + path[df_pathlen] == '/' && + strncmp(path, df_path, df_pathlen) == 0) { + output(opt, 3, + _("Removing %s to make room for subdirectory\n"), + df_path); + unlink(df_path); + unsorted_string_list_delete_item(&opt->df_conflict_file_set, + i, 0); + break; + } + } + + /* Make sure leading directories are created */ + status = safe_create_leading_directories_const(path); + if (status) { + if (status == SCLD_EXISTS) + /* something else exists */ + return err(opt, msg, path, _(": perhaps a D/F conflict?")); + return err(opt, msg, path, ""); + } + + /* + * Do not unlink a file in the work tree if we are not + * tracking it. + */ + if (would_lose_untracked(opt, path)) + return err(opt, _("refusing to lose untracked file at '%s'"), + path); + + /* Successful unlink is good.. */ + if (!unlink(path)) + return 0; + /* .. and so is no existing file */ + if (errno == ENOENT) + return 0; + /* .. but not some other error (who really cares what?) */ + return err(opt, msg, path, _(": perhaps a D/F conflict?")); +} + +static int update_file_flags(struct merge_options *opt, + const struct diff_filespec *contents, + const char *path, + int update_cache, + int update_wd) +{ + int ret = 0; + + if (opt->call_depth) + update_wd = 0; + + if (update_wd) { + enum object_type type; + void *buf; + unsigned long size; + + if (S_ISGITLINK(contents->mode)) { + /* + * We may later decide to recursively descend into + * the submodule directory and update its index + * and/or work tree, but we do not do that now. + */ + update_wd = 0; + goto update_index; + } + + buf = read_object_file(&contents->oid, &type, &size); + if (!buf) + return err(opt, _("cannot read object %s '%s'"), + oid_to_hex(&contents->oid), path); + if (type != OBJ_BLOB) { + ret = err(opt, _("blob expected for %s '%s'"), + oid_to_hex(&contents->oid), path); + goto free_buf; + } + if (S_ISREG(contents->mode)) { + struct strbuf strbuf = STRBUF_INIT; + if (convert_to_working_tree(opt->repo->index, path, buf, size, &strbuf)) { + free(buf); + size = strbuf.len; + buf = strbuf_detach(&strbuf, NULL); + } + } + + if (make_room_for_path(opt, path) < 0) { + update_wd = 0; + goto free_buf; + } + if (S_ISREG(contents->mode) || + (!has_symlinks && S_ISLNK(contents->mode))) { + int fd; + int mode = (contents->mode & 0100 ? 0777 : 0666); + + fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode); + if (fd < 0) { + ret = err(opt, _("failed to open '%s': %s"), + path, strerror(errno)); + goto free_buf; + } + write_in_full(fd, buf, size); + close(fd); + } else if (S_ISLNK(contents->mode)) { + char *lnk = xmemdupz(buf, size); + safe_create_leading_directories_const(path); + unlink(path); + if (symlink(lnk, path)) + ret = err(opt, _("failed to symlink '%s': %s"), + path, strerror(errno)); + free(lnk); + } else + ret = err(opt, + _("do not know what to do with %06o %s '%s'"), + contents->mode, oid_to_hex(&contents->oid), path); + free_buf: + free(buf); + } +update_index: + if (!ret && update_cache) + if (add_cacheinfo(opt, contents, path, 0, update_wd, + ADD_CACHE_OK_TO_ADD)) + return -1; + return ret; +} + +static int update_file(struct merge_options *opt, + int clean, + const struct diff_filespec *contents, + const char *path) +{ + return update_file_flags(opt, contents, path, + opt->call_depth || clean, !opt->call_depth); +} + +/* Low level file merging, update and removal */ + +struct merge_file_info { + struct diff_filespec blob; /* mostly use oid & mode; sometimes path */ + unsigned clean:1, + merge:1; +}; + +static int merge_3way(struct merge_options *opt, + mmbuffer_t *result_buf, + const struct diff_filespec *o, + const struct diff_filespec *a, + const struct diff_filespec *b, + const char *branch1, + const char *branch2, + const int extra_marker_size) +{ + mmfile_t orig, src1, src2; + struct ll_merge_options ll_opts = {0}; + char *base_name, *name1, *name2; + int merge_status; + + ll_opts.renormalize = opt->renormalize; + ll_opts.extra_marker_size = extra_marker_size; + ll_opts.xdl_opts = opt->xdl_opts; + + if (opt->call_depth) { + ll_opts.virtual_ancestor = 1; + ll_opts.variant = 0; + } else { + switch (opt->recursive_variant) { + case MERGE_RECURSIVE_OURS: + ll_opts.variant = XDL_MERGE_FAVOR_OURS; + break; + case MERGE_RECURSIVE_THEIRS: + ll_opts.variant = XDL_MERGE_FAVOR_THEIRS; + break; + default: + ll_opts.variant = 0; + break; + } + } + + assert(a->path && b->path); + if (strcmp(a->path, b->path) || + (opt->ancestor != NULL && strcmp(a->path, o->path) != 0)) { + base_name = opt->ancestor == NULL ? NULL : + mkpathdup("%s:%s", opt->ancestor, o->path); + name1 = mkpathdup("%s:%s", branch1, a->path); + name2 = mkpathdup("%s:%s", branch2, b->path); + } else { + base_name = opt->ancestor == NULL ? NULL : + mkpathdup("%s", opt->ancestor); + name1 = mkpathdup("%s", branch1); + name2 = mkpathdup("%s", branch2); + } + + read_mmblob(&orig, &o->oid); + read_mmblob(&src1, &a->oid); + read_mmblob(&src2, &b->oid); + + merge_status = ll_merge(result_buf, a->path, &orig, base_name, + &src1, name1, &src2, name2, + opt->repo->index, &ll_opts); + + free(base_name); + free(name1); + free(name2); + free(orig.ptr); + free(src1.ptr); + free(src2.ptr); + return merge_status; +} + +static int find_first_merges(struct repository *repo, + struct object_array *result, const char *path, + struct commit *a, struct commit *b) +{ + int i, j; + struct object_array merges = OBJECT_ARRAY_INIT; + struct commit *commit; + int contains_another; + + char merged_revision[GIT_MAX_HEXSZ + 2]; + const char *rev_args[] = { "rev-list", "--merges", "--ancestry-path", + "--all", merged_revision, NULL }; + struct rev_info revs; + struct setup_revision_opt rev_opts; + + memset(result, 0, sizeof(struct object_array)); + memset(&rev_opts, 0, sizeof(rev_opts)); + + /* get all revisions that merge commit a */ + xsnprintf(merged_revision, sizeof(merged_revision), "^%s", + oid_to_hex(&a->object.oid)); + repo_init_revisions(repo, &revs, NULL); + rev_opts.submodule = path; + /* FIXME: can't handle linked worktrees in submodules yet */ + revs.single_worktree = path != NULL; + setup_revisions(ARRAY_SIZE(rev_args)-1, rev_args, &revs, &rev_opts); + + /* save all revisions from the above list that contain b */ + if (prepare_revision_walk(&revs)) + die("revision walk setup failed"); + while ((commit = get_revision(&revs)) != NULL) { + struct object *o = &(commit->object); + if (in_merge_bases(b, commit)) + add_object_array(o, NULL, &merges); + } + reset_revision_walk(); + + /* Now we've got all merges that contain a and b. Prune all + * merges that contain another found merge and save them in + * result. + */ + for (i = 0; i < merges.nr; i++) { + struct commit *m1 = (struct commit *) merges.objects[i].item; + + contains_another = 0; + for (j = 0; j < merges.nr; j++) { + struct commit *m2 = (struct commit *) merges.objects[j].item; + if (i != j && in_merge_bases(m2, m1)) { + contains_another = 1; + break; + } + } + + if (!contains_another) + add_object_array(merges.objects[i].item, NULL, result); + } + + object_array_clear(&merges); + return result->nr; +} + +static void print_commit(struct commit *commit) +{ + struct strbuf sb = STRBUF_INIT; + struct pretty_print_context ctx = {0}; + ctx.date_mode.type = DATE_NORMAL; + format_commit_message(commit, " %h: %m %s", &sb, &ctx); + fprintf(stderr, "%s\n", sb.buf); + strbuf_release(&sb); +} + +static int is_valid(const struct diff_filespec *dfs) +{ + return dfs->mode != 0 && !is_null_oid(&dfs->oid); +} + +static int merge_submodule(struct merge_options *opt, + struct object_id *result, const char *path, + const struct object_id *base, const struct object_id *a, + const struct object_id *b) +{ + struct commit *commit_base, *commit_a, *commit_b; + int parent_count; + struct object_array merges; + + int i; + int search = !opt->call_depth; + + /* store a in result in case we fail */ + oidcpy(result, a); + + /* we can not handle deletion conflicts */ + if (is_null_oid(base)) + return 0; + if (is_null_oid(a)) + return 0; + if (is_null_oid(b)) + return 0; + + if (add_submodule_odb(path)) { + output(opt, 1, _("Failed to merge submodule %s (not checked out)"), path); + return 0; + } + + if (!(commit_base = lookup_commit_reference(opt->repo, base)) || + !(commit_a = lookup_commit_reference(opt->repo, a)) || + !(commit_b = lookup_commit_reference(opt->repo, b))) { + output(opt, 1, _("Failed to merge submodule %s (commits not present)"), path); + return 0; + } + + /* check whether both changes are forward */ + if (!in_merge_bases(commit_base, commit_a) || + !in_merge_bases(commit_base, commit_b)) { + output(opt, 1, _("Failed to merge submodule %s (commits don't follow merge-base)"), path); + return 0; + } + + /* Case #1: a is contained in b or vice versa */ + if (in_merge_bases(commit_a, commit_b)) { + oidcpy(result, b); + if (show(opt, 3)) { + output(opt, 3, _("Fast-forwarding submodule %s to the following commit:"), path); + output_commit_title(opt, commit_b); + } else if (show(opt, 2)) + output(opt, 2, _("Fast-forwarding submodule %s"), path); + else + ; /* no output */ + + return 1; + } + if (in_merge_bases(commit_b, commit_a)) { + oidcpy(result, a); + if (show(opt, 3)) { + output(opt, 3, _("Fast-forwarding submodule %s to the following commit:"), path); + output_commit_title(opt, commit_a); + } else if (show(opt, 2)) + output(opt, 2, _("Fast-forwarding submodule %s"), path); + else + ; /* no output */ + + return 1; + } + + /* + * Case #2: There are one or more merges that contain a and b in + * the submodule. If there is only one, then present it as a + * suggestion to the user, but leave it marked unmerged so the + * user needs to confirm the resolution. + */ + + /* Skip the search if makes no sense to the calling context. */ + if (!search) + return 0; + + /* find commit which merges them */ + parent_count = find_first_merges(opt->repo, &merges, path, + commit_a, commit_b); + switch (parent_count) { + case 0: + output(opt, 1, _("Failed to merge submodule %s (merge following commits not found)"), path); + break; + + case 1: + output(opt, 1, _("Failed to merge submodule %s (not fast-forward)"), path); + output(opt, 2, _("Found a possible merge resolution for the submodule:\n")); + print_commit((struct commit *) merges.objects[0].item); + output(opt, 2, _( + "If this is correct simply add it to the index " + "for example\n" + "by using:\n\n" + " git update-index --cacheinfo 160000 %s \"%s\"\n\n" + "which will accept this suggestion.\n"), + oid_to_hex(&merges.objects[0].item->oid), path); + break; + + default: + output(opt, 1, _("Failed to merge submodule %s (multiple merges found)"), path); + for (i = 0; i < merges.nr; i++) + print_commit((struct commit *) merges.objects[i].item); + } + + object_array_clear(&merges); + return 0; +} + +static int merge_mode_and_contents(struct merge_options *opt, + const struct diff_filespec *o, + const struct diff_filespec *a, + const struct diff_filespec *b, + const char *filename, + const char *branch1, + const char *branch2, + const int extra_marker_size, + struct merge_file_info *result) +{ + if (opt->branch1 != branch1) { + /* + * It's weird getting a reverse merge with HEAD on the bottom + * side of the conflict markers and the other branch on the + * top. Fix that. + */ + return merge_mode_and_contents(opt, o, b, a, + filename, + branch2, branch1, + extra_marker_size, result); + } + + result->merge = 0; + result->clean = 1; + + if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) { + result->clean = 0; + if (S_ISREG(a->mode)) { + result->blob.mode = a->mode; + oidcpy(&result->blob.oid, &a->oid); + } else { + result->blob.mode = b->mode; + oidcpy(&result->blob.oid, &b->oid); + } + } else { + if (!oid_eq(&a->oid, &o->oid) && !oid_eq(&b->oid, &o->oid)) + result->merge = 1; + + /* + * Merge modes + */ + if (a->mode == b->mode || a->mode == o->mode) + result->blob.mode = b->mode; + else { + result->blob.mode = a->mode; + if (b->mode != o->mode) { + result->clean = 0; + result->merge = 1; + } + } + + if (oid_eq(&a->oid, &b->oid) || oid_eq(&a->oid, &o->oid)) + oidcpy(&result->blob.oid, &b->oid); + else if (oid_eq(&b->oid, &o->oid)) + oidcpy(&result->blob.oid, &a->oid); + else if (S_ISREG(a->mode)) { + mmbuffer_t result_buf; + int ret = 0, merge_status; + + merge_status = merge_3way(opt, &result_buf, o, a, b, + branch1, branch2, + extra_marker_size); + + if ((merge_status < 0) || !result_buf.ptr) + ret = err(opt, _("Failed to execute internal merge")); + + if (!ret && + write_object_file(result_buf.ptr, result_buf.size, + blob_type, &result->blob.oid)) + ret = err(opt, _("Unable to add %s to database"), + a->path); + + free(result_buf.ptr); + if (ret) + return ret; + result->clean = (merge_status == 0); + } else if (S_ISGITLINK(a->mode)) { + result->clean = merge_submodule(opt, &result->blob.oid, + o->path, + &o->oid, + &a->oid, + &b->oid); + } else if (S_ISLNK(a->mode)) { + switch (opt->recursive_variant) { + case MERGE_RECURSIVE_NORMAL: + oidcpy(&result->blob.oid, &a->oid); + if (!oid_eq(&a->oid, &b->oid)) + result->clean = 0; + break; + case MERGE_RECURSIVE_OURS: + oidcpy(&result->blob.oid, &a->oid); + break; + case MERGE_RECURSIVE_THEIRS: + oidcpy(&result->blob.oid, &b->oid); + break; + } + } else + BUG("unsupported object type in the tree"); + } + + if (result->merge) + output(opt, 2, _("Auto-merging %s"), filename); + + return 0; +} + +static int handle_rename_via_dir(struct merge_options *opt, + struct rename_conflict_info *ci) +{ + /* + * Handle file adds that need to be renamed due to directory rename + * detection. This differs from handle_rename_normal, because + * there is no content merge to do; just move the file into the + * desired final location. + */ + const struct rename *ren = ci->ren1; + const struct diff_filespec *dest = ren->pair->two; + char *file_path = dest->path; + int mark_conflicted = (opt->detect_directory_renames == 1); + assert(ren->dir_rename_original_dest); + + if (!opt->call_depth && would_lose_untracked(opt, dest->path)) { + mark_conflicted = 1; + file_path = unique_path(opt, dest->path, ren->branch); + output(opt, 1, _("Error: Refusing to lose untracked file at %s; " + "writing to %s instead."), + dest->path, file_path); + } + + if (mark_conflicted) { + /* + * Write the file in worktree at file_path. In the index, + * only record the file at dest->path in the appropriate + * higher stage. + */ + if (update_file(opt, 0, dest, file_path)) + return -1; + if (file_path != dest->path) + free(file_path); + if (update_stages(opt, dest->path, NULL, + ren->branch == opt->branch1 ? dest : NULL, + ren->branch == opt->branch1 ? NULL : dest)) + return -1; + return 0; /* not clean, but conflicted */ + } else { + /* Update dest->path both in index and in worktree */ + if (update_file(opt, 1, dest, dest->path)) + return -1; + return 1; /* clean */ + } +} + +static int handle_change_delete(struct merge_options *opt, + const char *path, const char *old_path, + const struct diff_filespec *o, + const struct diff_filespec *changed, + const char *change_branch, + const char *delete_branch, + const char *change, const char *change_past) +{ + char *alt_path = NULL; + const char *update_path = path; + int ret = 0; + + if (dir_in_way(opt->repo->index, path, !opt->call_depth, 0) || + (!opt->call_depth && would_lose_untracked(opt, path))) { + update_path = alt_path = unique_path(opt, path, change_branch); + } + + if (opt->call_depth) { + /* + * We cannot arbitrarily accept either a_sha or b_sha as + * correct; since there is no true "middle point" between + * them, simply reuse the base version for virtual merge base. + */ + ret = remove_file_from_index(opt->repo->index, path); + if (!ret) + ret = update_file(opt, 0, o, update_path); + } else { + /* + * Despite the four nearly duplicate messages and argument + * lists below and the ugliness of the nested if-statements, + * having complete messages makes the job easier for + * translators. + * + * The slight variance among the cases is due to the fact + * that: + * 1) directory/file conflicts (in effect if + * !alt_path) could cause us to need to write the + * file to a different path. + * 2) renames (in effect if !old_path) could mean that + * there are two names for the path that the user + * may know the file by. + */ + if (!alt_path) { + if (!old_path) { + output(opt, 1, _("CONFLICT (%s/delete): %s deleted in %s " + "and %s in %s. Version %s of %s left in tree."), + change, path, delete_branch, change_past, + change_branch, change_branch, path); + } else { + output(opt, 1, _("CONFLICT (%s/delete): %s deleted in %s " + "and %s to %s in %s. Version %s of %s left in tree."), + change, old_path, delete_branch, change_past, path, + change_branch, change_branch, path); + } + } else { + if (!old_path) { + output(opt, 1, _("CONFLICT (%s/delete): %s deleted in %s " + "and %s in %s. Version %s of %s left in tree at %s."), + change, path, delete_branch, change_past, + change_branch, change_branch, path, alt_path); + } else { + output(opt, 1, _("CONFLICT (%s/delete): %s deleted in %s " + "and %s to %s in %s. Version %s of %s left in tree at %s."), + change, old_path, delete_branch, change_past, path, + change_branch, change_branch, path, alt_path); + } + } + /* + * No need to call update_file() on path when change_branch == + * opt->branch1 && !alt_path, since that would needlessly touch + * path. We could call update_file_flags() with update_cache=0 + * and update_wd=0, but that's a no-op. + */ + if (change_branch != opt->branch1 || alt_path) + ret = update_file(opt, 0, changed, update_path); + } + free(alt_path); + + return ret; +} + +static int handle_rename_delete(struct merge_options *opt, + struct rename_conflict_info *ci) +{ + const struct rename *ren = ci->ren1; + const struct diff_filespec *orig = ren->pair->one; + const struct diff_filespec *dest = ren->pair->two; + const char *rename_branch = ren->branch; + const char *delete_branch = (opt->branch1 == ren->branch ? + opt->branch2 : opt->branch1); + + if (handle_change_delete(opt, + opt->call_depth ? orig->path : dest->path, + opt->call_depth ? NULL : orig->path, + orig, dest, + rename_branch, delete_branch, + _("rename"), _("renamed"))) + return -1; + + if (opt->call_depth) + return remove_file_from_index(opt->repo->index, dest->path); + else + return update_stages(opt, dest->path, NULL, + rename_branch == opt->branch1 ? dest : NULL, + rename_branch == opt->branch1 ? NULL : dest); +} + +static int handle_file_collision(struct merge_options *opt, + const char *collide_path, + const char *prev_path1, + const char *prev_path2, + const char *branch1, const char *branch2, + struct diff_filespec *a, + struct diff_filespec *b) +{ + struct merge_file_info mfi; + struct diff_filespec null; + char *alt_path = NULL; + const char *update_path = collide_path; + + /* + * It's easiest to get the correct things into stage 2 and 3, and + * to make sure that the content merge puts HEAD before the other + * branch if we just ensure that branch1 == opt->branch1. So, simply + * flip arguments around if we don't have that. + */ + if (branch1 != opt->branch1) { + return handle_file_collision(opt, collide_path, + prev_path2, prev_path1, + branch2, branch1, + b, a); + } + + /* + * In the recursive case, we just opt to undo renames + */ + if (opt->call_depth && (prev_path1 || prev_path2)) { + /* Put first file (a->oid, a->mode) in its original spot */ + if (prev_path1) { + if (update_file(opt, 1, a, prev_path1)) + return -1; + } else { + if (update_file(opt, 1, a, collide_path)) + return -1; + } + + /* Put second file (b->oid, b->mode) in its original spot */ + if (prev_path2) { + if (update_file(opt, 1, b, prev_path2)) + return -1; + } else { + if (update_file(opt, 1, b, collide_path)) + return -1; + } + + /* Don't leave something at collision path if unrenaming both */ + if (prev_path1 && prev_path2) + remove_file(opt, 1, collide_path, 0); + + return 0; + } + + /* Remove rename sources if rename/add or rename/rename(2to1) */ + if (prev_path1) + remove_file(opt, 1, prev_path1, + opt->call_depth || would_lose_untracked(opt, prev_path1)); + if (prev_path2) + remove_file(opt, 1, prev_path2, + opt->call_depth || would_lose_untracked(opt, prev_path2)); + + /* + * Remove the collision path, if it wouldn't cause dirty contents + * or an untracked file to get lost. We'll either overwrite with + * merged contents, or just write out to differently named files. + */ + if (was_dirty(opt, collide_path)) { + output(opt, 1, _("Refusing to lose dirty file at %s"), + collide_path); + update_path = alt_path = unique_path(opt, collide_path, "merged"); + } else if (would_lose_untracked(opt, collide_path)) { + /* + * Only way we get here is if both renames were from + * a directory rename AND user had an untracked file + * at the location where both files end up after the + * two directory renames. See testcase 10d of t6043. + */ + output(opt, 1, _("Refusing to lose untracked file at " + "%s, even though it's in the way."), + collide_path); + update_path = alt_path = unique_path(opt, collide_path, "merged"); + } else { + /* + * FIXME: It's possible that the two files are identical + * and that the current working copy happens to match, in + * which case we are unnecessarily touching the working + * tree file. It's not a likely enough scenario that I + * want to code up the checks for it and a better fix is + * available if we restructure how unpack_trees() and + * merge-recursive interoperate anyway, so punting for + * now... + */ + remove_file(opt, 0, collide_path, 0); + } + + /* Store things in diff_filespecs for functions that need it */ + null.path = (char *)collide_path; + oidcpy(&null.oid, &null_oid); + null.mode = 0; + + if (merge_mode_and_contents(opt, &null, a, b, collide_path, + branch1, branch2, opt->call_depth * 2, &mfi)) + return -1; + mfi.clean &= !alt_path; + if (update_file(opt, mfi.clean, &mfi.blob, update_path)) + return -1; + if (!mfi.clean && !opt->call_depth && + update_stages(opt, collide_path, NULL, a, b)) + return -1; + free(alt_path); + /* + * FIXME: If both a & b both started with conflicts (only possible + * if they came from a rename/rename(2to1)), but had IDENTICAL + * contents including those conflicts, then in the next line we claim + * it was clean. If someone cares about this case, we should have the + * caller notify us if we started with conflicts. + */ + return mfi.clean; +} + +static int handle_rename_add(struct merge_options *opt, + struct rename_conflict_info *ci) +{ + /* a was renamed to c, and a separate c was added. */ + struct diff_filespec *a = ci->ren1->pair->one; + struct diff_filespec *c = ci->ren1->pair->two; + char *path = c->path; + char *prev_path_desc; + struct merge_file_info mfi; + + const char *rename_branch = ci->ren1->branch; + const char *add_branch = (opt->branch1 == rename_branch ? + opt->branch2 : opt->branch1); + int other_stage = (ci->ren1->branch == opt->branch1 ? 3 : 2); + + output(opt, 1, _("CONFLICT (rename/add): " + "Rename %s->%s in %s. Added %s in %s"), + a->path, c->path, rename_branch, + c->path, add_branch); + + prev_path_desc = xstrfmt("version of %s from %s", path, a->path); + ci->ren1->src_entry->stages[other_stage].path = a->path; + if (merge_mode_and_contents(opt, a, c, + &ci->ren1->src_entry->stages[other_stage], + prev_path_desc, + opt->branch1, opt->branch2, + 1 + opt->call_depth * 2, &mfi)) + return -1; + free(prev_path_desc); + + ci->ren1->dst_entry->stages[other_stage].path = mfi.blob.path = c->path; + return handle_file_collision(opt, + c->path, a->path, NULL, + rename_branch, add_branch, + &mfi.blob, + &ci->ren1->dst_entry->stages[other_stage]); +} + +static char *find_path_for_conflict(struct merge_options *opt, + const char *path, + const char *branch1, + const char *branch2) +{ + char *new_path = NULL; + if (dir_in_way(opt->repo->index, path, !opt->call_depth, 0)) { + new_path = unique_path(opt, path, branch1); + output(opt, 1, _("%s is a directory in %s adding " + "as %s instead"), + path, branch2, new_path); + } else if (would_lose_untracked(opt, path)) { + new_path = unique_path(opt, path, branch1); + output(opt, 1, _("Refusing to lose untracked file" + " at %s; adding as %s instead"), + path, new_path); + } + + return new_path; +} + +static int handle_rename_rename_1to2(struct merge_options *opt, + struct rename_conflict_info *ci) +{ + /* One file was renamed in both branches, but to different names. */ + struct merge_file_info mfi; + struct diff_filespec *add; + struct diff_filespec *o = ci->ren1->pair->one; + struct diff_filespec *a = ci->ren1->pair->two; + struct diff_filespec *b = ci->ren2->pair->two; + char *path_desc; + + output(opt, 1, _("CONFLICT (rename/rename): " + "Rename \"%s\"->\"%s\" in branch \"%s\" " + "rename \"%s\"->\"%s\" in \"%s\"%s"), + o->path, a->path, ci->ren1->branch, + o->path, b->path, ci->ren2->branch, + opt->call_depth ? _(" (left unresolved)") : ""); + + path_desc = xstrfmt("%s and %s, both renamed from %s", + a->path, b->path, o->path); + if (merge_mode_and_contents(opt, o, a, b, path_desc, + ci->ren1->branch, ci->ren2->branch, + opt->call_depth * 2, &mfi)) + return -1; + free(path_desc); + + if (opt->call_depth) { + /* + * FIXME: For rename/add-source conflicts (if we could detect + * such), this is wrong. We should instead find a unique + * pathname and then either rename the add-source file to that + * unique path, or use that unique path instead of src here. + */ + if (update_file(opt, 0, &mfi.blob, o->path)) + return -1; + + /* + * Above, we put the merged content at the merge-base's + * path. Now we usually need to delete both a->path and + * b->path. However, the rename on each side of the merge + * could also be involved in a rename/add conflict. In + * such cases, we should keep the added file around, + * resolving the conflict at that path in its favor. + */ + add = &ci->ren1->dst_entry->stages[2 ^ 1]; + if (is_valid(add)) { + if (update_file(opt, 0, add, a->path)) + return -1; + } + else + remove_file_from_index(opt->repo->index, a->path); + add = &ci->ren2->dst_entry->stages[3 ^ 1]; + if (is_valid(add)) { + if (update_file(opt, 0, add, b->path)) + return -1; + } + else + remove_file_from_index(opt->repo->index, b->path); + } else { + /* + * For each destination path, we need to see if there is a + * rename/add collision. If not, we can write the file out + * to the specified location. + */ + add = &ci->ren1->dst_entry->stages[2 ^ 1]; + if (is_valid(add)) { + add->path = mfi.blob.path = a->path; + if (handle_file_collision(opt, a->path, + NULL, NULL, + ci->ren1->branch, + ci->ren2->branch, + &mfi.blob, add) < 0) + return -1; + } else { + char *new_path = find_path_for_conflict(opt, a->path, + ci->ren1->branch, + ci->ren2->branch); + if (update_file(opt, 0, &mfi.blob, + new_path ? new_path : a->path)) + return -1; + free(new_path); + if (update_stages(opt, a->path, NULL, a, NULL)) + return -1; + } + + add = &ci->ren2->dst_entry->stages[3 ^ 1]; + if (is_valid(add)) { + add->path = mfi.blob.path = b->path; + if (handle_file_collision(opt, b->path, + NULL, NULL, + ci->ren1->branch, + ci->ren2->branch, + add, &mfi.blob) < 0) + return -1; + } else { + char *new_path = find_path_for_conflict(opt, b->path, + ci->ren2->branch, + ci->ren1->branch); + if (update_file(opt, 0, &mfi.blob, + new_path ? new_path : b->path)) + return -1; + free(new_path); + if (update_stages(opt, b->path, NULL, NULL, b)) + return -1; + } + } + + return 0; +} + +static int handle_rename_rename_2to1(struct merge_options *opt, + struct rename_conflict_info *ci) +{ + /* Two files, a & b, were renamed to the same thing, c. */ + struct diff_filespec *a = ci->ren1->pair->one; + struct diff_filespec *b = ci->ren2->pair->one; + struct diff_filespec *c1 = ci->ren1->pair->two; + struct diff_filespec *c2 = ci->ren2->pair->two; + char *path = c1->path; /* == c2->path */ + char *path_side_1_desc; + char *path_side_2_desc; + struct merge_file_info mfi_c1; + struct merge_file_info mfi_c2; + int ostage1, ostage2; + + output(opt, 1, _("CONFLICT (rename/rename): " + "Rename %s->%s in %s. " + "Rename %s->%s in %s"), + a->path, c1->path, ci->ren1->branch, + b->path, c2->path, ci->ren2->branch); + + path_side_1_desc = xstrfmt("version of %s from %s", path, a->path); + path_side_2_desc = xstrfmt("version of %s from %s", path, b->path); + ostage1 = ci->ren1->branch == opt->branch1 ? 3 : 2; + ostage2 = ostage1 ^ 1; + ci->ren1->src_entry->stages[ostage1].path = a->path; + ci->ren2->src_entry->stages[ostage2].path = b->path; + if (merge_mode_and_contents(opt, a, c1, + &ci->ren1->src_entry->stages[ostage1], + path_side_1_desc, + opt->branch1, opt->branch2, + 1 + opt->call_depth * 2, &mfi_c1) || + merge_mode_and_contents(opt, b, + &ci->ren2->src_entry->stages[ostage2], + c2, path_side_2_desc, + opt->branch1, opt->branch2, + 1 + opt->call_depth * 2, &mfi_c2)) + return -1; + free(path_side_1_desc); + free(path_side_2_desc); + mfi_c1.blob.path = path; + mfi_c2.blob.path = path; + + return handle_file_collision(opt, path, a->path, b->path, + ci->ren1->branch, ci->ren2->branch, + &mfi_c1.blob, &mfi_c2.blob); +} + +/* + * Get the diff_filepairs changed between o_tree and tree. + */ +static struct diff_queue_struct *get_diffpairs(struct merge_options *opt, + struct tree *o_tree, + struct tree *tree) +{ + struct diff_queue_struct *ret; + struct diff_options opts; + + repo_diff_setup(opt->repo, &opts); + opts.flags.recursive = 1; + opts.flags.rename_empty = 0; + opts.detect_rename = merge_detect_rename(opt); + /* + * We do not have logic to handle the detection of copies. In + * fact, it may not even make sense to add such logic: would we + * really want a change to a base file to be propagated through + * multiple other files by a merge? + */ + if (opts.detect_rename > DIFF_DETECT_RENAME) + opts.detect_rename = DIFF_DETECT_RENAME; + opts.rename_limit = opt->merge_rename_limit >= 0 ? opt->merge_rename_limit : + opt->diff_rename_limit >= 0 ? opt->diff_rename_limit : + 1000; + opts.rename_score = opt->rename_score; + opts.show_rename_progress = opt->show_rename_progress; + opts.output_format = DIFF_FORMAT_NO_OUTPUT; + diff_setup_done(&opts); + diff_tree_oid(&o_tree->object.oid, &tree->object.oid, "", &opts); + diffcore_std(&opts); + if (opts.needed_rename_limit > opt->needed_rename_limit) + opt->needed_rename_limit = opts.needed_rename_limit; + + ret = xmalloc(sizeof(*ret)); + *ret = diff_queued_diff; + + opts.output_format = DIFF_FORMAT_NO_OUTPUT; + diff_queued_diff.nr = 0; + diff_queued_diff.queue = NULL; + diff_flush(&opts); + return ret; +} + +static int tree_has_path(struct repository *r, struct tree *tree, + const char *path) +{ + struct object_id hashy; + unsigned short mode_o; + + return !get_tree_entry(r, + &tree->object.oid, path, + &hashy, &mode_o); +} + +/* + * Return a new string that replaces the beginning portion (which matches + * entry->dir), with entry->new_dir. In perl-speak: + * new_path_name = (old_path =~ s/entry->dir/entry->new_dir/); + * NOTE: + * Caller must ensure that old_path starts with entry->dir + '/'. + */ +static char *apply_dir_rename(struct dir_rename_entry *entry, + const char *old_path) +{ + struct strbuf new_path = STRBUF_INIT; + int oldlen, newlen; + + if (entry->non_unique_new_dir) + return NULL; + + oldlen = strlen(entry->dir); + newlen = entry->new_dir.len + (strlen(old_path) - oldlen) + 1; + strbuf_grow(&new_path, newlen); + strbuf_addbuf(&new_path, &entry->new_dir); + strbuf_addstr(&new_path, &old_path[oldlen]); + + return strbuf_detach(&new_path, NULL); +} + +static void get_renamed_dir_portion(const char *old_path, const char *new_path, + char **old_dir, char **new_dir) +{ + char *end_of_old, *end_of_new; + int old_len, new_len; + + *old_dir = NULL; + *new_dir = NULL; + + /* + * For + * "a/b/c/d/e/foo.c" -> "a/b/some/thing/else/e/foo.c" + * the "e/foo.c" part is the same, we just want to know that + * "a/b/c/d" was renamed to "a/b/some/thing/else" + * so, for this example, this function returns "a/b/c/d" in + * *old_dir and "a/b/some/thing/else" in *new_dir. + * + * Also, if the basename of the file changed, we don't care. We + * want to know which portion of the directory, if any, changed. + */ + end_of_old = strrchr(old_path, '/'); + end_of_new = strrchr(new_path, '/'); + + if (end_of_old == NULL || end_of_new == NULL) + return; + while (*--end_of_new == *--end_of_old && + end_of_old != old_path && + end_of_new != new_path) + ; /* Do nothing; all in the while loop */ + /* + * We've found the first non-matching character in the directory + * paths. That means the current directory we were comparing + * represents the rename. Move end_of_old and end_of_new back + * to the full directory name. + */ + if (*end_of_old == '/') + end_of_old++; + if (*end_of_old != '/') + end_of_new++; + end_of_old = strchr(end_of_old, '/'); + end_of_new = strchr(end_of_new, '/'); + + /* + * It may have been the case that old_path and new_path were the same + * directory all along. Don't claim a rename if they're the same. + */ + old_len = end_of_old - old_path; + new_len = end_of_new - new_path; + + if (old_len != new_len || strncmp(old_path, new_path, old_len)) { + *old_dir = xstrndup(old_path, old_len); + *new_dir = xstrndup(new_path, new_len); + } +} + +static void remove_hashmap_entries(struct hashmap *dir_renames, + struct string_list *items_to_remove) +{ + int i; + struct dir_rename_entry *entry; + + for (i = 0; i < items_to_remove->nr; i++) { + entry = items_to_remove->items[i].util; + hashmap_remove(dir_renames, entry, NULL); + } + string_list_clear(items_to_remove, 0); +} + +/* + * See if there is a directory rename for path, and if there are any file + * level conflicts for the renamed location. If there is a rename and + * there are no conflicts, return the new name. Otherwise, return NULL. + */ +static char *handle_path_level_conflicts(struct merge_options *opt, + const char *path, + struct dir_rename_entry *entry, + struct hashmap *collisions, + struct tree *tree) +{ + char *new_path = NULL; + struct collision_entry *collision_ent; + int clean = 1; + struct strbuf collision_paths = STRBUF_INIT; + + /* + * entry has the mapping of old directory name to new directory name + * that we want to apply to path. + */ + new_path = apply_dir_rename(entry, path); + + if (!new_path) { + /* This should only happen when entry->non_unique_new_dir set */ + if (!entry->non_unique_new_dir) + BUG("entry->non_unqiue_dir not set and !new_path"); + output(opt, 1, _("CONFLICT (directory rename split): " + "Unclear where to place %s because directory " + "%s was renamed to multiple other directories, " + "with no destination getting a majority of the " + "files."), + path, entry->dir); + clean = 0; + return NULL; + } + + /* + * The caller needs to have ensured that it has pre-populated + * collisions with all paths that map to new_path. Do a quick check + * to ensure that's the case. + */ + collision_ent = collision_find_entry(collisions, new_path); + if (collision_ent == NULL) + BUG("collision_ent is NULL"); + + /* + * Check for one-sided add/add/.../add conflicts, i.e. + * where implicit renames from the other side doing + * directory rename(s) can affect this side of history + * to put multiple paths into the same location. Warn + * and bail on directory renames for such paths. + */ + if (collision_ent->reported_already) { + clean = 0; + } else if (tree_has_path(opt->repo, tree, new_path)) { + collision_ent->reported_already = 1; + strbuf_add_separated_string_list(&collision_paths, ", ", + &collision_ent->source_files); + output(opt, 1, _("CONFLICT (implicit dir rename): Existing " + "file/dir at %s in the way of implicit " + "directory rename(s) putting the following " + "path(s) there: %s."), + new_path, collision_paths.buf); + clean = 0; + } else if (collision_ent->source_files.nr > 1) { + collision_ent->reported_already = 1; + strbuf_add_separated_string_list(&collision_paths, ", ", + &collision_ent->source_files); + output(opt, 1, _("CONFLICT (implicit dir rename): Cannot map " + "more than one path to %s; implicit directory " + "renames tried to put these paths there: %s"), + new_path, collision_paths.buf); + clean = 0; + } + + /* Free memory we no longer need */ + strbuf_release(&collision_paths); + if (!clean && new_path) { + free(new_path); + return NULL; + } + + return new_path; +} + +/* + * There are a couple things we want to do at the directory level: + * 1. Check for both sides renaming to the same thing, in order to avoid + * implicit renaming of files that should be left in place. (See + * testcase 6b in t6043 for details.) + * 2. Prune directory renames if there are still files left in the + * the original directory. These represent a partial directory rename, + * i.e. a rename where only some of the files within the directory + * were renamed elsewhere. (Technically, this could be done earlier + * in get_directory_renames(), except that would prevent us from + * doing the previous check and thus failing testcase 6b.) + * 3. Check for rename/rename(1to2) conflicts (at the directory level). + * In the future, we could potentially record this info as well and + * omit reporting rename/rename(1to2) conflicts for each path within + * the affected directories, thus cleaning up the merge output. + * NOTE: We do NOT check for rename/rename(2to1) conflicts at the + * directory level, because merging directories is fine. If it + * causes conflicts for files within those merged directories, then + * that should be detected at the individual path level. + */ +static void handle_directory_level_conflicts(struct merge_options *opt, + struct hashmap *dir_re_head, + struct tree *head, + struct hashmap *dir_re_merge, + struct tree *merge) +{ + struct hashmap_iter iter; + struct dir_rename_entry *head_ent; + struct dir_rename_entry *merge_ent; + + struct string_list remove_from_head = STRING_LIST_INIT_NODUP; + struct string_list remove_from_merge = STRING_LIST_INIT_NODUP; + + hashmap_iter_init(dir_re_head, &iter); + while ((head_ent = hashmap_iter_next(&iter))) { + merge_ent = dir_rename_find_entry(dir_re_merge, head_ent->dir); + if (merge_ent && + !head_ent->non_unique_new_dir && + !merge_ent->non_unique_new_dir && + !strbuf_cmp(&head_ent->new_dir, &merge_ent->new_dir)) { + /* 1. Renamed identically; remove it from both sides */ + string_list_append(&remove_from_head, + head_ent->dir)->util = head_ent; + strbuf_release(&head_ent->new_dir); + string_list_append(&remove_from_merge, + merge_ent->dir)->util = merge_ent; + strbuf_release(&merge_ent->new_dir); + } else if (tree_has_path(opt->repo, head, head_ent->dir)) { + /* 2. This wasn't a directory rename after all */ + string_list_append(&remove_from_head, + head_ent->dir)->util = head_ent; + strbuf_release(&head_ent->new_dir); + } + } + + remove_hashmap_entries(dir_re_head, &remove_from_head); + remove_hashmap_entries(dir_re_merge, &remove_from_merge); + + hashmap_iter_init(dir_re_merge, &iter); + while ((merge_ent = hashmap_iter_next(&iter))) { + head_ent = dir_rename_find_entry(dir_re_head, merge_ent->dir); + if (tree_has_path(opt->repo, merge, merge_ent->dir)) { + /* 2. This wasn't a directory rename after all */ + string_list_append(&remove_from_merge, + merge_ent->dir)->util = merge_ent; + } else if (head_ent && + !head_ent->non_unique_new_dir && + !merge_ent->non_unique_new_dir) { + /* 3. rename/rename(1to2) */ + /* + * We can assume it's not rename/rename(1to1) because + * that was case (1), already checked above. So we + * know that head_ent->new_dir and merge_ent->new_dir + * are different strings. + */ + output(opt, 1, _("CONFLICT (rename/rename): " + "Rename directory %s->%s in %s. " + "Rename directory %s->%s in %s"), + head_ent->dir, head_ent->new_dir.buf, opt->branch1, + head_ent->dir, merge_ent->new_dir.buf, opt->branch2); + string_list_append(&remove_from_head, + head_ent->dir)->util = head_ent; + strbuf_release(&head_ent->new_dir); + string_list_append(&remove_from_merge, + merge_ent->dir)->util = merge_ent; + strbuf_release(&merge_ent->new_dir); + } + } + + remove_hashmap_entries(dir_re_head, &remove_from_head); + remove_hashmap_entries(dir_re_merge, &remove_from_merge); +} + +static struct hashmap *get_directory_renames(struct diff_queue_struct *pairs) +{ + struct hashmap *dir_renames; + struct hashmap_iter iter; + struct dir_rename_entry *entry; + int i; + + /* + * Typically, we think of a directory rename as all files from a + * certain directory being moved to a target directory. However, + * what if someone first moved two files from the original + * directory in one commit, and then renamed the directory + * somewhere else in a later commit? At merge time, we just know + * that files from the original directory went to two different + * places, and that the bulk of them ended up in the same place. + * We want each directory rename to represent where the bulk of the + * files from that directory end up; this function exists to find + * where the bulk of the files went. + * + * The first loop below simply iterates through the list of file + * renames, finding out how often each directory rename pair + * possibility occurs. + */ + dir_renames = xmalloc(sizeof(*dir_renames)); + dir_rename_init(dir_renames); + for (i = 0; i < pairs->nr; ++i) { + struct string_list_item *item; + int *count; + struct diff_filepair *pair = pairs->queue[i]; + char *old_dir, *new_dir; + + /* File not part of directory rename if it wasn't renamed */ + if (pair->status != 'R') + continue; + + get_renamed_dir_portion(pair->one->path, pair->two->path, + &old_dir, &new_dir); + if (!old_dir) + /* Directory didn't change at all; ignore this one. */ + continue; + + entry = dir_rename_find_entry(dir_renames, old_dir); + if (!entry) { + entry = xmalloc(sizeof(*entry)); + dir_rename_entry_init(entry, old_dir); + hashmap_put(dir_renames, entry); + } else { + free(old_dir); + } + item = string_list_lookup(&entry->possible_new_dirs, new_dir); + if (!item) { + item = string_list_insert(&entry->possible_new_dirs, + new_dir); + item->util = xcalloc(1, sizeof(int)); + } else { + free(new_dir); + } + count = item->util; + *count += 1; + } + + /* + * For each directory with files moved out of it, we find out which + * target directory received the most files so we can declare it to + * be the "winning" target location for the directory rename. This + * winner gets recorded in new_dir. If there is no winner + * (multiple target directories received the same number of files), + * we set non_unique_new_dir. Once we've determined the winner (or + * that there is no winner), we no longer need possible_new_dirs. + */ + hashmap_iter_init(dir_renames, &iter); + while ((entry = hashmap_iter_next(&iter))) { + int max = 0; + int bad_max = 0; + char *best = NULL; + + for (i = 0; i < entry->possible_new_dirs.nr; i++) { + int *count = entry->possible_new_dirs.items[i].util; + + if (*count == max) + bad_max = max; + else if (*count > max) { + max = *count; + best = entry->possible_new_dirs.items[i].string; + } + } + if (bad_max == max) + entry->non_unique_new_dir = 1; + else { + assert(entry->new_dir.len == 0); + strbuf_addstr(&entry->new_dir, best); + } + /* + * The relevant directory sub-portion of the original full + * filepaths were xstrndup'ed before inserting into + * possible_new_dirs, and instead of manually iterating the + * list and free'ing each, just lie and tell + * possible_new_dirs that it did the strdup'ing so that it + * will free them for us. + */ + entry->possible_new_dirs.strdup_strings = 1; + string_list_clear(&entry->possible_new_dirs, 1); + } + + return dir_renames; +} + +static struct dir_rename_entry *check_dir_renamed(const char *path, + struct hashmap *dir_renames) +{ + char *temp = xstrdup(path); + char *end; + struct dir_rename_entry *entry = NULL; + + while ((end = strrchr(temp, '/'))) { + *end = '\0'; + entry = dir_rename_find_entry(dir_renames, temp); + if (entry) + break; + } + free(temp); + return entry; +} + +static void compute_collisions(struct hashmap *collisions, + struct hashmap *dir_renames, + struct diff_queue_struct *pairs) +{ + int i; + + /* + * Multiple files can be mapped to the same path due to directory + * renames done by the other side of history. Since that other + * side of history could have merged multiple directories into one, + * if our side of history added the same file basename to each of + * those directories, then all N of them would get implicitly + * renamed by the directory rename detection into the same path, + * and we'd get an add/add/.../add conflict, and all those adds + * from *this* side of history. This is not representable in the + * index, and users aren't going to easily be able to make sense of + * it. So we need to provide a good warning about what's + * happening, and fall back to no-directory-rename detection + * behavior for those paths. + * + * See testcases 9e and all of section 5 from t6043 for examples. + */ + collision_init(collisions); + + for (i = 0; i < pairs->nr; ++i) { + struct dir_rename_entry *dir_rename_ent; + struct collision_entry *collision_ent; + char *new_path; + struct diff_filepair *pair = pairs->queue[i]; + + if (pair->status != 'A' && pair->status != 'R') + continue; + dir_rename_ent = check_dir_renamed(pair->two->path, + dir_renames); + if (!dir_rename_ent) + continue; + + new_path = apply_dir_rename(dir_rename_ent, pair->two->path); + if (!new_path) + /* + * dir_rename_ent->non_unique_new_path is true, which + * means there is no directory rename for us to use, + * which means it won't cause us any additional + * collisions. + */ + continue; + collision_ent = collision_find_entry(collisions, new_path); + if (!collision_ent) { + collision_ent = xcalloc(1, + sizeof(struct collision_entry)); + hashmap_entry_init(collision_ent, strhash(new_path)); + hashmap_put(collisions, collision_ent); + collision_ent->target_file = new_path; + } else { + free(new_path); + } + string_list_insert(&collision_ent->source_files, + pair->two->path); + } +} + +static char *check_for_directory_rename(struct merge_options *opt, + const char *path, + struct tree *tree, + struct hashmap *dir_renames, + struct hashmap *dir_rename_exclusions, + struct hashmap *collisions, + int *clean_merge) +{ + char *new_path = NULL; + struct dir_rename_entry *entry = check_dir_renamed(path, dir_renames); + struct dir_rename_entry *oentry = NULL; + + if (!entry) + return new_path; + + /* + * This next part is a little weird. We do not want to do an + * implicit rename into a directory we renamed on our side, because + * that will result in a spurious rename/rename(1to2) conflict. An + * example: + * Base commit: dumbdir/afile, otherdir/bfile + * Side 1: smrtdir/afile, otherdir/bfile + * Side 2: dumbdir/afile, dumbdir/bfile + * Here, while working on Side 1, we could notice that otherdir was + * renamed/merged to dumbdir, and change the diff_filepair for + * otherdir/bfile into a rename into dumbdir/bfile. However, Side + * 2 will notice the rename from dumbdir to smrtdir, and do the + * transitive rename to move it from dumbdir/bfile to + * smrtdir/bfile. That gives us bfile in dumbdir vs being in + * smrtdir, a rename/rename(1to2) conflict. We really just want + * the file to end up in smrtdir. And the way to achieve that is + * to not let Side1 do the rename to dumbdir, since we know that is + * the source of one of our directory renames. + * + * That's why oentry and dir_rename_exclusions is here. + * + * As it turns out, this also prevents N-way transient rename + * confusion; See testcases 9c and 9d of t6043. + */ + oentry = dir_rename_find_entry(dir_rename_exclusions, entry->new_dir.buf); + if (oentry) { + output(opt, 1, _("WARNING: Avoiding applying %s -> %s rename " + "to %s, because %s itself was renamed."), + entry->dir, entry->new_dir.buf, path, entry->new_dir.buf); + } else { + new_path = handle_path_level_conflicts(opt, path, entry, + collisions, tree); + *clean_merge &= (new_path != NULL); + } + + return new_path; +} + +static void apply_directory_rename_modifications(struct merge_options *opt, + struct diff_filepair *pair, + char *new_path, + struct rename *re, + struct tree *tree, + struct tree *o_tree, + struct tree *a_tree, + struct tree *b_tree, + struct string_list *entries) +{ + struct string_list_item *item; + int stage = (tree == a_tree ? 2 : 3); + int update_wd; + + /* + * In all cases where we can do directory rename detection, + * unpack_trees() will have read pair->two->path into the + * index and the working copy. We need to remove it so that + * we can instead place it at new_path. It is guaranteed to + * not be untracked (unpack_trees() would have errored out + * saying the file would have been overwritten), but it might + * be dirty, though. + */ + update_wd = !was_dirty(opt, pair->two->path); + if (!update_wd) + output(opt, 1, _("Refusing to lose dirty file at %s"), + pair->two->path); + remove_file(opt, 1, pair->two->path, !update_wd); + + /* Find or create a new re->dst_entry */ + item = string_list_lookup(entries, new_path); + if (item) { + /* + * Since we're renaming on this side of history, and it's + * due to a directory rename on the other side of history + * (which we only allow when the directory in question no + * longer exists on the other side of history), the + * original entry for re->dst_entry is no longer + * necessary... + */ + re->dst_entry->processed = 1; + + /* + * ...because we'll be using this new one. + */ + re->dst_entry = item->util; + } else { + /* + * re->dst_entry is for the before-dir-rename path, and we + * need it to hold information for the after-dir-rename + * path. Before creating a new entry, we need to mark the + * old one as unnecessary (...unless it is shared by + * src_entry, i.e. this didn't use to be a rename, in which + * case we can just allow the normal processing to happen + * for it). + */ + if (pair->status == 'R') + re->dst_entry->processed = 1; + + re->dst_entry = insert_stage_data(opt->repo, new_path, + o_tree, a_tree, b_tree, + entries); + item = string_list_insert(entries, new_path); + item->util = re->dst_entry; + } + + /* + * Update the stage_data with the information about the path we are + * moving into place. That slot will be empty and available for us + * to write to because of the collision checks in + * handle_path_level_conflicts(). In other words, + * re->dst_entry->stages[stage].oid will be the null_oid, so it's + * open for us to write to. + * + * It may be tempting to actually update the index at this point as + * well, using update_stages_for_stage_data(), but as per the big + * "NOTE" in update_stages(), doing so will modify the current + * in-memory index which will break calls to would_lose_untracked() + * that we need to make. Instead, we need to just make sure that + * the various handle_rename_*() functions update the index + * explicitly rather than relying on unpack_trees() to have done it. + */ + get_tree_entry(opt->repo, + &tree->object.oid, + pair->two->path, + &re->dst_entry->stages[stage].oid, + &re->dst_entry->stages[stage].mode); + + /* + * Record the original change status (or 'type' of change). If it + * was originally an add ('A'), this lets us differentiate later + * between a RENAME_DELETE conflict and RENAME_VIA_DIR (they + * otherwise look the same). If it was originally a rename ('R'), + * this lets us remember and report accurately about the transitive + * renaming that occurred via the directory rename detection. Also, + * record the original destination name. + */ + re->dir_rename_original_type = pair->status; + re->dir_rename_original_dest = pair->two->path; + + /* + * We don't actually look at pair->status again, but it seems + * pedagogically correct to adjust it. + */ + pair->status = 'R'; + + /* + * Finally, record the new location. + */ + pair->two->path = new_path; +} + +/* + * Get information of all renames which occurred in 'pairs', making use of + * any implicit directory renames inferred from the other side of history. + * We need the three trees in the merge ('o_tree', 'a_tree' and 'b_tree') + * to be able to associate the correct cache entries with the rename + * information; tree is always equal to either a_tree or b_tree. + */ +static struct string_list *get_renames(struct merge_options *opt, + const char *branch, + struct diff_queue_struct *pairs, + struct hashmap *dir_renames, + struct hashmap *dir_rename_exclusions, + struct tree *tree, + struct tree *o_tree, + struct tree *a_tree, + struct tree *b_tree, + struct string_list *entries, + int *clean_merge) +{ + int i; + struct hashmap collisions; + struct hashmap_iter iter; + struct collision_entry *e; + struct string_list *renames; + + compute_collisions(&collisions, dir_renames, pairs); + renames = xcalloc(1, sizeof(struct string_list)); + + for (i = 0; i < pairs->nr; ++i) { + struct string_list_item *item; + struct rename *re; + struct diff_filepair *pair = pairs->queue[i]; + char *new_path; /* non-NULL only with directory renames */ + + if (pair->status != 'A' && pair->status != 'R') { + diff_free_filepair(pair); + continue; + } + new_path = check_for_directory_rename(opt, pair->two->path, tree, + dir_renames, + dir_rename_exclusions, + &collisions, + clean_merge); + if (pair->status != 'R' && !new_path) { + diff_free_filepair(pair); + continue; + } + + re = xmalloc(sizeof(*re)); + re->processed = 0; + re->pair = pair; + re->branch = branch; + re->dir_rename_original_type = '\0'; + re->dir_rename_original_dest = NULL; + item = string_list_lookup(entries, re->pair->one->path); + if (!item) + re->src_entry = insert_stage_data(opt->repo, + re->pair->one->path, + o_tree, a_tree, b_tree, entries); + else + re->src_entry = item->util; + + item = string_list_lookup(entries, re->pair->two->path); + if (!item) + re->dst_entry = insert_stage_data(opt->repo, + re->pair->two->path, + o_tree, a_tree, b_tree, entries); + else + re->dst_entry = item->util; + item = string_list_insert(renames, pair->one->path); + item->util = re; + if (new_path) + apply_directory_rename_modifications(opt, pair, new_path, + re, tree, o_tree, + a_tree, b_tree, + entries); + } + + hashmap_iter_init(&collisions, &iter); + while ((e = hashmap_iter_next(&iter))) { + free(e->target_file); + string_list_clear(&e->source_files, 0); + } + hashmap_free(&collisions, 1); + return renames; +} + +static int process_renames(struct merge_options *opt, + struct string_list *a_renames, + struct string_list *b_renames) +{ + int clean_merge = 1, i, j; + struct string_list a_by_dst = STRING_LIST_INIT_NODUP; + struct string_list b_by_dst = STRING_LIST_INIT_NODUP; + const struct rename *sre; + + for (i = 0; i < a_renames->nr; i++) { + sre = a_renames->items[i].util; + string_list_insert(&a_by_dst, sre->pair->two->path)->util + = (void *)sre; + } + for (i = 0; i < b_renames->nr; i++) { + sre = b_renames->items[i].util; + string_list_insert(&b_by_dst, sre->pair->two->path)->util + = (void *)sre; + } + + for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) { + struct string_list *renames1, *renames2Dst; + struct rename *ren1 = NULL, *ren2 = NULL; + const char *ren1_src, *ren1_dst; + struct string_list_item *lookup; + + if (i >= a_renames->nr) { + ren2 = b_renames->items[j++].util; + } else if (j >= b_renames->nr) { + ren1 = a_renames->items[i++].util; + } else { + int compare = strcmp(a_renames->items[i].string, + b_renames->items[j].string); + if (compare <= 0) + ren1 = a_renames->items[i++].util; + if (compare >= 0) + ren2 = b_renames->items[j++].util; + } + + /* TODO: refactor, so that 1/2 are not needed */ + if (ren1) { + renames1 = a_renames; + renames2Dst = &b_by_dst; + } else { + renames1 = b_renames; + renames2Dst = &a_by_dst; + SWAP(ren2, ren1); + } + + if (ren1->processed) + continue; + ren1->processed = 1; + ren1->dst_entry->processed = 1; + /* BUG: We should only mark src_entry as processed if we + * are not dealing with a rename + add-source case. + */ + ren1->src_entry->processed = 1; + + ren1_src = ren1->pair->one->path; + ren1_dst = ren1->pair->two->path; + + if (ren2) { + /* One file renamed on both sides */ + const char *ren2_src = ren2->pair->one->path; + const char *ren2_dst = ren2->pair->two->path; + enum rename_type rename_type; + if (strcmp(ren1_src, ren2_src) != 0) + BUG("ren1_src != ren2_src"); + ren2->dst_entry->processed = 1; + ren2->processed = 1; + if (strcmp(ren1_dst, ren2_dst) != 0) { + rename_type = RENAME_ONE_FILE_TO_TWO; + clean_merge = 0; + } else { + rename_type = RENAME_ONE_FILE_TO_ONE; + /* BUG: We should only remove ren1_src in + * the base stage (think of rename + + * add-source cases). + */ + remove_file(opt, 1, ren1_src, 1); + update_entry(ren1->dst_entry, + ren1->pair->one, + ren1->pair->two, + ren2->pair->two); + } + setup_rename_conflict_info(rename_type, opt, ren1, ren2); + } else if ((lookup = string_list_lookup(renames2Dst, ren1_dst))) { + /* Two different files renamed to the same thing */ + char *ren2_dst; + ren2 = lookup->util; + ren2_dst = ren2->pair->two->path; + if (strcmp(ren1_dst, ren2_dst) != 0) + BUG("ren1_dst != ren2_dst"); + + clean_merge = 0; + ren2->processed = 1; + /* + * BUG: We should only mark src_entry as processed + * if we are not dealing with a rename + add-source + * case. + */ + ren2->src_entry->processed = 1; + + setup_rename_conflict_info(RENAME_TWO_FILES_TO_ONE, + opt, ren1, ren2); + } else { + /* Renamed in 1, maybe changed in 2 */ + /* we only use sha1 and mode of these */ + struct diff_filespec src_other, dst_other; + int try_merge; + + /* + * unpack_trees loads entries from common-commit + * into stage 1, from head-commit into stage 2, and + * from merge-commit into stage 3. We keep track + * of which side corresponds to the rename. + */ + int renamed_stage = a_renames == renames1 ? 2 : 3; + int other_stage = a_renames == renames1 ? 3 : 2; + + /* BUG: We should only remove ren1_src in the base + * stage and in other_stage (think of rename + + * add-source case). + */ + remove_file(opt, 1, ren1_src, + renamed_stage == 2 || !was_tracked(opt, ren1_src)); + + oidcpy(&src_other.oid, + &ren1->src_entry->stages[other_stage].oid); + src_other.mode = ren1->src_entry->stages[other_stage].mode; + oidcpy(&dst_other.oid, + &ren1->dst_entry->stages[other_stage].oid); + dst_other.mode = ren1->dst_entry->stages[other_stage].mode; + try_merge = 0; + + if (oid_eq(&src_other.oid, &null_oid) && + ren1->dir_rename_original_type == 'A') { + setup_rename_conflict_info(RENAME_VIA_DIR, + opt, ren1, NULL); + } else if (oid_eq(&src_other.oid, &null_oid)) { + setup_rename_conflict_info(RENAME_DELETE, + opt, ren1, NULL); + } else if ((dst_other.mode == ren1->pair->two->mode) && + oid_eq(&dst_other.oid, &ren1->pair->two->oid)) { + /* + * Added file on the other side identical to + * the file being renamed: clean merge. + * Also, there is no need to overwrite the + * file already in the working copy, so call + * update_file_flags() instead of + * update_file(). + */ + if (update_file_flags(opt, + ren1->pair->two, + ren1_dst, + 1, /* update_cache */ + 0 /* update_wd */)) + clean_merge = -1; + } else if (!oid_eq(&dst_other.oid, &null_oid)) { + /* + * Probably not a clean merge, but it's + * premature to set clean_merge to 0 here, + * because if the rename merges cleanly and + * the merge exactly matches the newly added + * file, then the merge will be clean. + */ + setup_rename_conflict_info(RENAME_ADD, + opt, ren1, NULL); + } else + try_merge = 1; + + if (clean_merge < 0) + goto cleanup_and_return; + if (try_merge) { + struct diff_filespec *o, *a, *b; + src_other.path = (char *)ren1_src; + + o = ren1->pair->one; + if (a_renames == renames1) { + a = ren1->pair->two; + b = &src_other; + } else { + b = ren1->pair->two; + a = &src_other; + } + update_entry(ren1->dst_entry, o, a, b); + setup_rename_conflict_info(RENAME_NORMAL, + opt, ren1, NULL); + } + } + } +cleanup_and_return: + string_list_clear(&a_by_dst, 0); + string_list_clear(&b_by_dst, 0); + + return clean_merge; +} + +struct rename_info { + struct string_list *head_renames; + struct string_list *merge_renames; +}; + +static void initial_cleanup_rename(struct diff_queue_struct *pairs, + struct hashmap *dir_renames) +{ + struct hashmap_iter iter; + struct dir_rename_entry *e; + + hashmap_iter_init(dir_renames, &iter); + while ((e = hashmap_iter_next(&iter))) { + free(e->dir); + strbuf_release(&e->new_dir); + /* possible_new_dirs already cleared in get_directory_renames */ + } + hashmap_free(dir_renames, 1); + free(dir_renames); + + free(pairs->queue); + free(pairs); +} + +static int detect_and_process_renames(struct merge_options *opt, + struct tree *common, + struct tree *head, + struct tree *merge, + struct string_list *entries, + struct rename_info *ri) +{ + struct diff_queue_struct *head_pairs, *merge_pairs; + struct hashmap *dir_re_head, *dir_re_merge; + int clean = 1; + + ri->head_renames = NULL; + ri->merge_renames = NULL; + + if (!merge_detect_rename(opt)) + return 1; + + head_pairs = get_diffpairs(opt, common, head); + merge_pairs = get_diffpairs(opt, common, merge); + + if ((opt->detect_directory_renames == 2) || + (opt->detect_directory_renames == 1 && !opt->call_depth)) { + dir_re_head = get_directory_renames(head_pairs); + dir_re_merge = get_directory_renames(merge_pairs); + + handle_directory_level_conflicts(opt, + dir_re_head, head, + dir_re_merge, merge); + } else { + dir_re_head = xmalloc(sizeof(*dir_re_head)); + dir_re_merge = xmalloc(sizeof(*dir_re_merge)); + dir_rename_init(dir_re_head); + dir_rename_init(dir_re_merge); + } + + ri->head_renames = get_renames(opt, opt->branch1, head_pairs, + dir_re_merge, dir_re_head, head, + common, head, merge, entries, + &clean); + if (clean < 0) + goto cleanup; + ri->merge_renames = get_renames(opt, opt->branch2, merge_pairs, + dir_re_head, dir_re_merge, merge, + common, head, merge, entries, + &clean); + if (clean < 0) + goto cleanup; + clean &= process_renames(opt, ri->head_renames, ri->merge_renames); + +cleanup: + /* + * Some cleanup is deferred until cleanup_renames() because the + * data structures are still needed and referenced in + * process_entry(). But there are a few things we can free now. + */ + initial_cleanup_rename(head_pairs, dir_re_head); + initial_cleanup_rename(merge_pairs, dir_re_merge); + + return clean; +} + +static void final_cleanup_rename(struct string_list *rename) +{ + const struct rename *re; + int i; + + if (rename == NULL) + return; + + for (i = 0; i < rename->nr; i++) { + re = rename->items[i].util; + diff_free_filepair(re->pair); + } + string_list_clear(rename, 1); + free(rename); +} + +static void final_cleanup_renames(struct rename_info *re_info) +{ + final_cleanup_rename(re_info->head_renames); + final_cleanup_rename(re_info->merge_renames); +} + +static int read_oid_strbuf(struct merge_options *opt, + const struct object_id *oid, + struct strbuf *dst) +{ + void *buf; + enum object_type type; + unsigned long size; + buf = read_object_file(oid, &type, &size); + if (!buf) + return err(opt, _("cannot read object %s"), oid_to_hex(oid)); + if (type != OBJ_BLOB) { + free(buf); + return err(opt, _("object %s is not a blob"), oid_to_hex(oid)); + } + strbuf_attach(dst, buf, size, size + 1); + return 0; +} + +static int blob_unchanged(struct merge_options *opt, + const struct diff_filespec *o, + const struct diff_filespec *a, + int renormalize, const char *path) +{ + struct strbuf obuf = STRBUF_INIT; + struct strbuf abuf = STRBUF_INIT; + int ret = 0; /* assume changed for safety */ + const struct index_state *idx = opt->repo->index; + + if (a->mode != o->mode) + return 0; + if (oid_eq(&o->oid, &a->oid)) + return 1; + if (!renormalize) + return 0; + + if (read_oid_strbuf(opt, &o->oid, &obuf) || + read_oid_strbuf(opt, &a->oid, &abuf)) + goto error_return; + /* + * Note: binary | is used so that both renormalizations are + * performed. Comparison can be skipped if both files are + * unchanged since their sha1s have already been compared. + */ + if (renormalize_buffer(idx, path, obuf.buf, obuf.len, &obuf) | + renormalize_buffer(idx, path, abuf.buf, abuf.len, &abuf)) + ret = (obuf.len == abuf.len && !memcmp(obuf.buf, abuf.buf, obuf.len)); + +error_return: + strbuf_release(&obuf); + strbuf_release(&abuf); + return ret; +} + +static int handle_modify_delete(struct merge_options *opt, + const char *path, + const struct diff_filespec *o, + const struct diff_filespec *a, + const struct diff_filespec *b) +{ + const char *modify_branch, *delete_branch; + const struct diff_filespec *changed; + + if (is_valid(a)) { + modify_branch = opt->branch1; + delete_branch = opt->branch2; + changed = a; + } else { + modify_branch = opt->branch2; + delete_branch = opt->branch1; + changed = b; + } + + return handle_change_delete(opt, + path, NULL, + o, changed, + modify_branch, delete_branch, + _("modify"), _("modified")); +} + +static int handle_content_merge(struct merge_file_info *mfi, + struct merge_options *opt, + const char *path, + int is_dirty, + const struct diff_filespec *o, + const struct diff_filespec *a, + const struct diff_filespec *b, + struct rename_conflict_info *ci) +{ + const char *reason = _("content"); + unsigned df_conflict_remains = 0; + + if (!is_valid(o)) + reason = _("add/add"); + + assert(o->path && a->path && b->path); + if (ci && dir_in_way(opt->repo->index, path, !opt->call_depth, + S_ISGITLINK(ci->ren1->pair->two->mode))) + df_conflict_remains = 1; + + if (merge_mode_and_contents(opt, o, a, b, path, + opt->branch1, opt->branch2, + opt->call_depth * 2, mfi)) + return -1; + + /* + * We can skip updating the working tree file iff: + * a) The merge is clean + * b) The merge matches what was in HEAD (content, mode, pathname) + * c) The target path is usable (i.e. not involved in D/F conflict) + */ + if (mfi->clean && was_tracked_and_matches(opt, path, &mfi->blob) && + !df_conflict_remains) { + int pos; + struct cache_entry *ce; + + output(opt, 3, _("Skipped %s (merged same as existing)"), path); + if (add_cacheinfo(opt, &mfi->blob, path, + 0, (!opt->call_depth && !is_dirty), 0)) + return -1; + /* + * However, add_cacheinfo() will delete the old cache entry + * and add a new one. We need to copy over any skip_worktree + * flag to avoid making the file appear as if it were + * deleted by the user. + */ + pos = index_name_pos(&opt->orig_index, path, strlen(path)); + ce = opt->orig_index.cache[pos]; + if (ce_skip_worktree(ce)) { + pos = index_name_pos(opt->repo->index, path, strlen(path)); + ce = opt->repo->index->cache[pos]; + ce->ce_flags |= CE_SKIP_WORKTREE; + } + return mfi->clean; + } + + if (!mfi->clean) { + if (S_ISGITLINK(mfi->blob.mode)) + reason = _("submodule"); + output(opt, 1, _("CONFLICT (%s): Merge conflict in %s"), + reason, path); + if (ci && !df_conflict_remains) + if (update_stages(opt, path, o, a, b)) + return -1; + } + + if (df_conflict_remains || is_dirty) { + char *new_path; + if (opt->call_depth) { + remove_file_from_index(opt->repo->index, path); + } else { + if (!mfi->clean) { + if (update_stages(opt, path, o, a, b)) + return -1; + } else { + int file_from_stage2 = was_tracked(opt, path); + + if (update_stages(opt, path, NULL, + file_from_stage2 ? &mfi->blob : NULL, + file_from_stage2 ? NULL : &mfi->blob)) + return -1; + } + + } + new_path = unique_path(opt, path, ci->ren1->branch); + if (is_dirty) { + output(opt, 1, _("Refusing to lose dirty file at %s"), + path); + } + output(opt, 1, _("Adding as %s instead"), new_path); + if (update_file(opt, 0, &mfi->blob, new_path)) { + free(new_path); + return -1; + } + free(new_path); + mfi->clean = 0; + } else if (update_file(opt, mfi->clean, &mfi->blob, path)) + return -1; + return !is_dirty && mfi->clean; +} + +static int handle_rename_normal(struct merge_options *opt, + const char *path, + const struct diff_filespec *o, + const struct diff_filespec *a, + const struct diff_filespec *b, + struct rename_conflict_info *ci) +{ + struct rename *ren = ci->ren1; + struct merge_file_info mfi; + int clean; + int side = (ren->branch == opt->branch1 ? 2 : 3); + + /* Merge the content and write it out */ + clean = handle_content_merge(&mfi, opt, path, was_dirty(opt, path), + o, a, b, ci); + + if (clean && opt->detect_directory_renames == 1 && + ren->dir_rename_original_dest) { + if (update_stages(opt, path, + NULL, + side == 2 ? &mfi.blob : NULL, + side == 2 ? NULL : &mfi.blob)) + return -1; + clean = 0; /* not clean, but conflicted */ + } + return clean; +} + +static void dir_rename_warning(const char *msg, + int is_add, + int clean, + struct merge_options *opt, + struct rename *ren) +{ + const char *other_branch; + other_branch = (ren->branch == opt->branch1 ? + opt->branch2 : opt->branch1); + if (is_add) { + output(opt, clean ? 2 : 1, msg, + ren->pair->one->path, ren->branch, + other_branch, ren->pair->two->path); + return; + } + output(opt, clean ? 2 : 1, msg, + ren->pair->one->path, ren->dir_rename_original_dest, ren->branch, + other_branch, ren->pair->two->path); +} +static int warn_about_dir_renamed_entries(struct merge_options *opt, + struct rename *ren) +{ + const char *msg; + int clean = 1, is_add; + + if (!ren) + return clean; + + /* Return early if ren was not affected/created by a directory rename */ + if (!ren->dir_rename_original_dest) + return clean; + + /* Sanity checks */ + assert(opt->detect_directory_renames > 0); + assert(ren->dir_rename_original_type == 'A' || + ren->dir_rename_original_type == 'R'); + + /* Check whether to treat directory renames as a conflict */ + clean = (opt->detect_directory_renames == 2); + + is_add = (ren->dir_rename_original_type == 'A'); + if (ren->dir_rename_original_type == 'A' && clean) { + msg = _("Path updated: %s added in %s inside a " + "directory that was renamed in %s; moving it to %s."); + } else if (ren->dir_rename_original_type == 'A' && !clean) { + msg = _("CONFLICT (file location): %s added in %s " + "inside a directory that was renamed in %s, " + "suggesting it should perhaps be moved to %s."); + } else if (ren->dir_rename_original_type == 'R' && clean) { + msg = _("Path updated: %s renamed to %s in %s, inside a " + "directory that was renamed in %s; moving it to %s."); + } else if (ren->dir_rename_original_type == 'R' && !clean) { + msg = _("CONFLICT (file location): %s renamed to %s in %s, " + "inside a directory that was renamed in %s, " + "suggesting it should perhaps be moved to %s."); + } else { + BUG("Impossible dir_rename_original_type/clean combination"); + } + dir_rename_warning(msg, is_add, clean, opt, ren); + + return clean; +} + +/* Per entry merge function */ +static int process_entry(struct merge_options *opt, + const char *path, struct stage_data *entry) +{ + int clean_merge = 1; + int normalize = opt->renormalize; + + struct diff_filespec *o = &entry->stages[1]; + struct diff_filespec *a = &entry->stages[2]; + struct diff_filespec *b = &entry->stages[3]; + int o_valid = is_valid(o); + int a_valid = is_valid(a); + int b_valid = is_valid(b); + o->path = a->path = b->path = (char*)path; + + entry->processed = 1; + if (entry->rename_conflict_info) { + struct rename_conflict_info *ci = entry->rename_conflict_info; + struct diff_filespec *temp; + int path_clean; + + path_clean = warn_about_dir_renamed_entries(opt, ci->ren1); + path_clean &= warn_about_dir_renamed_entries(opt, ci->ren2); + + /* + * For cases with a single rename, {o,a,b}->path have all been + * set to the rename target path; we need to set two of these + * back to the rename source. + * For rename/rename conflicts, we'll manually fix paths below. + */ + temp = (opt->branch1 == ci->ren1->branch) ? b : a; + o->path = temp->path = ci->ren1->pair->one->path; + if (ci->ren2) { + assert(opt->branch1 == ci->ren1->branch); + } + + switch (ci->rename_type) { + case RENAME_NORMAL: + case RENAME_ONE_FILE_TO_ONE: + clean_merge = handle_rename_normal(opt, path, o, a, b, + ci); + break; + case RENAME_VIA_DIR: + clean_merge = handle_rename_via_dir(opt, ci); + break; + case RENAME_ADD: + /* + * Probably unclean merge, but if the renamed file + * merges cleanly and the result can then be + * two-way merged cleanly with the added file, I + * guess it's a clean merge? + */ + clean_merge = handle_rename_add(opt, ci); + break; + case RENAME_DELETE: + clean_merge = 0; + if (handle_rename_delete(opt, ci)) + clean_merge = -1; + break; + case RENAME_ONE_FILE_TO_TWO: + /* + * Manually fix up paths; note: + * ren[12]->pair->one->path are equal. + */ + o->path = ci->ren1->pair->one->path; + a->path = ci->ren1->pair->two->path; + b->path = ci->ren2->pair->two->path; + + clean_merge = 0; + if (handle_rename_rename_1to2(opt, ci)) + clean_merge = -1; + break; + case RENAME_TWO_FILES_TO_ONE: + /* + * Manually fix up paths; note, + * ren[12]->pair->two->path are actually equal. + */ + o->path = NULL; + a->path = ci->ren1->pair->two->path; + b->path = ci->ren2->pair->two->path; + + /* + * Probably unclean merge, but if the two renamed + * files merge cleanly and the two resulting files + * can then be two-way merged cleanly, I guess it's + * a clean merge? + */ + clean_merge = handle_rename_rename_2to1(opt, ci); + break; + default: + entry->processed = 0; + break; + } + if (path_clean < clean_merge) + clean_merge = path_clean; + } else if (o_valid && (!a_valid || !b_valid)) { + /* Case A: Deleted in one */ + if ((!a_valid && !b_valid) || + (!b_valid && blob_unchanged(opt, o, a, normalize, path)) || + (!a_valid && blob_unchanged(opt, o, b, normalize, path))) { + /* Deleted in both or deleted in one and + * unchanged in the other */ + if (a_valid) + output(opt, 2, _("Removing %s"), path); + /* do not touch working file if it did not exist */ + remove_file(opt, 1, path, !a_valid); + } else { + /* Modify/delete; deleted side may have put a directory in the way */ + clean_merge = 0; + if (handle_modify_delete(opt, path, o, a, b)) + clean_merge = -1; + } + } else if ((!o_valid && a_valid && !b_valid) || + (!o_valid && !a_valid && b_valid)) { + /* Case B: Added in one. */ + /* [nothing|directory] -> ([nothing|directory], file) */ + + const char *add_branch; + const char *other_branch; + const char *conf; + const struct diff_filespec *contents; + + if (a_valid) { + add_branch = opt->branch1; + other_branch = opt->branch2; + contents = a; + conf = _("file/directory"); + } else { + add_branch = opt->branch2; + other_branch = opt->branch1; + contents = b; + conf = _("directory/file"); + } + if (dir_in_way(opt->repo->index, path, + !opt->call_depth && !S_ISGITLINK(a->mode), + 0)) { + char *new_path = unique_path(opt, path, add_branch); + clean_merge = 0; + output(opt, 1, _("CONFLICT (%s): There is a directory with name %s in %s. " + "Adding %s as %s"), + conf, path, other_branch, path, new_path); + if (update_file(opt, 0, contents, new_path)) + clean_merge = -1; + else if (opt->call_depth) + remove_file_from_index(opt->repo->index, path); + free(new_path); + } else { + output(opt, 2, _("Adding %s"), path); + /* do not overwrite file if already present */ + if (update_file_flags(opt, contents, path, 1, !a_valid)) + clean_merge = -1; + } + } else if (a_valid && b_valid) { + if (!o_valid) { + /* Case C: Added in both (check for same permissions) */ + output(opt, 1, + _("CONFLICT (add/add): Merge conflict in %s"), + path); + clean_merge = handle_file_collision(opt, + path, NULL, NULL, + opt->branch1, + opt->branch2, + a, b); + } else { + /* case D: Modified in both, but differently. */ + struct merge_file_info mfi; + int is_dirty = 0; /* unpack_trees would have bailed if dirty */ + clean_merge = handle_content_merge(&mfi, opt, path, + is_dirty, + o, a, b, NULL); + } + } else if (!o_valid && !a_valid && !b_valid) { + /* + * this entry was deleted altogether. a_mode == 0 means + * we had that path and want to actively remove it. + */ + remove_file(opt, 1, path, !a->mode); + } else + BUG("fatal merge failure, shouldn't happen."); + + return clean_merge; +} + +int merge_trees(struct merge_options *opt, + struct tree *head, + struct tree *merge, + struct tree *common, + struct tree **result) +{ + struct index_state *istate = opt->repo->index; + int code, clean; + struct strbuf sb = STRBUF_INIT; + + if (!opt->call_depth && repo_index_has_changes(opt->repo, head, &sb)) { + err(opt, _("Your local changes to the following files would be overwritten by merge:\n %s"), + sb.buf); + return -1; + } + + if (opt->subtree_shift) { + merge = shift_tree_object(opt->repo, head, merge, opt->subtree_shift); + common = shift_tree_object(opt->repo, head, common, opt->subtree_shift); + } + + if (oid_eq(&common->object.oid, &merge->object.oid)) { + output(opt, 0, _("Already up to date!")); + *result = head; + return 1; + } + + code = unpack_trees_start(opt, common, head, merge); + + if (code != 0) { + if (show(opt, 4) || opt->call_depth) + err(opt, _("merging of trees %s and %s failed"), + oid_to_hex(&head->object.oid), + oid_to_hex(&merge->object.oid)); + unpack_trees_finish(opt); + return -1; + } + + if (unmerged_index(istate)) { + struct string_list *entries; + struct rename_info re_info; + int i; + /* + * Only need the hashmap while processing entries, so + * initialize it here and free it when we are done running + * through the entries. Keeping it in the merge_options as + * opposed to decaring a local hashmap is for convenience + * so that we don't have to pass it to around. + */ + hashmap_init(&opt->current_file_dir_set, path_hashmap_cmp, NULL, 512); + get_files_dirs(opt, head); + get_files_dirs(opt, merge); + + entries = get_unmerged(opt->repo->index); + clean = detect_and_process_renames(opt, common, head, merge, + entries, &re_info); + record_df_conflict_files(opt, entries); + if (clean < 0) + goto cleanup; + for (i = entries->nr-1; 0 <= i; i--) { + const char *path = entries->items[i].string; + struct stage_data *e = entries->items[i].util; + if (!e->processed) { + int ret = process_entry(opt, path, e); + if (!ret) + clean = 0; + else if (ret < 0) { + clean = ret; + goto cleanup; + } + } + } + for (i = 0; i < entries->nr; i++) { + struct stage_data *e = entries->items[i].util; + if (!e->processed) + BUG("unprocessed path??? %s", + entries->items[i].string); + } + + cleanup: + final_cleanup_renames(&re_info); + + string_list_clear(entries, 1); + free(entries); + + hashmap_free(&opt->current_file_dir_set, 1); + + if (clean < 0) { + unpack_trees_finish(opt); + return clean; + } + } + else + clean = 1; + + unpack_trees_finish(opt); + + if (opt->call_depth && !(*result = write_tree_from_memory(opt))) + return -1; + + return clean; +} + +static struct commit_list *reverse_commit_list(struct commit_list *list) +{ + struct commit_list *next = NULL, *current, *backup; + for (current = list; current; current = backup) { + backup = current->next; + current->next = next; + next = current; + } + return next; +} + +/* + * Merge the commits h1 and h2, return the resulting virtual + * commit object and a flag indicating the cleanness of the merge. + */ +int merge_recursive(struct merge_options *opt, + struct commit *h1, + struct commit *h2, + struct commit_list *ca, + struct commit **result) +{ + struct commit_list *iter; + struct commit *merged_common_ancestors; + struct tree *mrtree; + int clean; + + if (show(opt, 4)) { + output(opt, 4, _("Merging:")); + output_commit_title(opt, h1); + output_commit_title(opt, h2); + } + + if (!ca) { + ca = get_merge_bases(h1, h2); + ca = reverse_commit_list(ca); + } + + if (show(opt, 5)) { + unsigned cnt = commit_list_count(ca); + + output(opt, 5, Q_("found %u common ancestor:", + "found %u common ancestors:", cnt), cnt); + for (iter = ca; iter; iter = iter->next) + output_commit_title(opt, iter->item); + } + + merged_common_ancestors = pop_commit(&ca); + if (merged_common_ancestors == NULL) { + /* if there is no common ancestor, use an empty tree */ + struct tree *tree; + + tree = lookup_tree(opt->repo, opt->repo->hash_algo->empty_tree); + merged_common_ancestors = make_virtual_commit(opt->repo, tree, "ancestor"); + } + + for (iter = ca; iter; iter = iter->next) { + const char *saved_b1, *saved_b2; + opt->call_depth++; + /* + * When the merge fails, the result contains files + * with conflict markers. The cleanness flag is + * ignored (unless indicating an error), it was never + * actually used, as result of merge_trees has always + * overwritten it: the committed "conflicts" were + * already resolved. + */ + discard_index(opt->repo->index); + saved_b1 = opt->branch1; + saved_b2 = opt->branch2; + opt->branch1 = "Temporary merge branch 1"; + opt->branch2 = "Temporary merge branch 2"; + if (merge_recursive(opt, merged_common_ancestors, iter->item, + NULL, &merged_common_ancestors) < 0) + return -1; + opt->branch1 = saved_b1; + opt->branch2 = saved_b2; + opt->call_depth--; + + if (!merged_common_ancestors) + return err(opt, _("merge returned no commit")); + } + + discard_index(opt->repo->index); + if (!opt->call_depth) + repo_read_index(opt->repo); + + opt->ancestor = "merged common ancestors"; + clean = merge_trees(opt, get_commit_tree(h1), get_commit_tree(h2), + get_commit_tree(merged_common_ancestors), + &mrtree); + if (clean < 0) { + flush_output(opt); + return clean; + } + + if (opt->call_depth) { + *result = make_virtual_commit(opt->repo, mrtree, "merged tree"); + commit_list_insert(h1, &(*result)->parents); + commit_list_insert(h2, &(*result)->parents->next); + } + flush_output(opt); + if (!opt->call_depth && opt->buffer_output < 2) + strbuf_release(&opt->obuf); + if (show(opt, 2)) + diff_warn_rename_limit("merge.renamelimit", + opt->needed_rename_limit, 0); + return clean; +} + +static struct commit *get_ref(struct repository *repo, const struct object_id *oid, + const char *name) +{ + struct object *object; + + object = deref_tag(repo, parse_object(repo, oid), + name, strlen(name)); + if (!object) + return NULL; + if (object->type == OBJ_TREE) + return make_virtual_commit(repo, (struct tree*)object, name); + if (object->type != OBJ_COMMIT) + return NULL; + if (parse_commit((struct commit *)object)) + return NULL; + return (struct commit *)object; +} + +int merge_recursive_generic(struct merge_options *opt, + const struct object_id *head, + const struct object_id *merge, + int num_base_list, + const struct object_id **base_list, + struct commit **result) +{ + int clean; + struct lock_file lock = LOCK_INIT; + struct commit *head_commit = get_ref(opt->repo, head, opt->branch1); + struct commit *next_commit = get_ref(opt->repo, merge, opt->branch2); + struct commit_list *ca = NULL; + + if (base_list) { + int i; + for (i = 0; i < num_base_list; ++i) { + struct commit *base; + if (!(base = get_ref(opt->repo, base_list[i], oid_to_hex(base_list[i])))) + return err(opt, _("Could not parse object '%s'"), + oid_to_hex(base_list[i])); + commit_list_insert(base, &ca); + } + } + + repo_hold_locked_index(opt->repo, &lock, LOCK_DIE_ON_ERROR); + clean = merge_recursive(opt, head_commit, next_commit, ca, + result); + if (clean < 0) { + rollback_lock_file(&lock); + return clean; + } + + if (write_locked_index(opt->repo->index, &lock, + COMMIT_LOCK | SKIP_IF_UNCHANGED)) + return err(opt, _("Unable to write index.")); + + return clean ? 0 : 1; +} + +static void merge_recursive_config(struct merge_options *opt) +{ + char *value = NULL; + git_config_get_int("merge.verbosity", &opt->verbosity); + git_config_get_int("diff.renamelimit", &opt->diff_rename_limit); + git_config_get_int("merge.renamelimit", &opt->merge_rename_limit); + if (!git_config_get_string("diff.renames", &value)) { + opt->diff_detect_rename = git_config_rename("diff.renames", value); + free(value); + } + if (!git_config_get_string("merge.renames", &value)) { + opt->merge_detect_rename = git_config_rename("merge.renames", value); + free(value); + } + if (!git_config_get_string("merge.directoryrenames", &value)) { + int boolval = git_parse_maybe_bool(value); + if (0 <= boolval) { + opt->detect_directory_renames = boolval ? 2 : 0; + } else if (!strcasecmp(value, "conflict")) { + opt->detect_directory_renames = 1; + } /* avoid erroring on values from future versions of git */ + free(value); + } + git_config(git_xmerge_config, NULL); +} + +void init_merge_options(struct merge_options *opt, + struct repository *repo) +{ + const char *merge_verbosity; + memset(opt, 0, sizeof(struct merge_options)); + opt->repo = repo; + opt->verbosity = 2; + opt->buffer_output = 1; + opt->diff_rename_limit = -1; + opt->merge_rename_limit = -1; + opt->renormalize = 0; + opt->diff_detect_rename = -1; + opt->merge_detect_rename = -1; + opt->detect_directory_renames = 1; + merge_recursive_config(opt); + merge_verbosity = getenv("GIT_MERGE_VERBOSITY"); + if (merge_verbosity) + opt->verbosity = strtol(merge_verbosity, NULL, 10); + if (opt->verbosity >= 5) + opt->buffer_output = 0; + strbuf_init(&opt->obuf, 0); + string_list_init(&opt->df_conflict_file_set, 1); +} + +int parse_merge_opt(struct merge_options *opt, const char *s) +{ + const char *arg; + + if (!s || !*s) + return -1; + if (!strcmp(s, "ours")) + opt->recursive_variant = MERGE_RECURSIVE_OURS; + else if (!strcmp(s, "theirs")) + opt->recursive_variant = MERGE_RECURSIVE_THEIRS; + else if (!strcmp(s, "subtree")) + opt->subtree_shift = ""; + else if (skip_prefix(s, "subtree=", &arg)) + opt->subtree_shift = arg; + else if (!strcmp(s, "patience")) + opt->xdl_opts = DIFF_WITH_ALG(opt, PATIENCE_DIFF); + else if (!strcmp(s, "histogram")) + opt->xdl_opts = DIFF_WITH_ALG(opt, HISTOGRAM_DIFF); + else if (skip_prefix(s, "diff-algorithm=", &arg)) { + long value = parse_algorithm_value(arg); + if (value < 0) + return -1; + /* clear out previous settings */ + DIFF_XDL_CLR(opt, NEED_MINIMAL); + opt->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK; + opt->xdl_opts |= value; + } + else if (!strcmp(s, "ignore-space-change")) + DIFF_XDL_SET(opt, IGNORE_WHITESPACE_CHANGE); + else if (!strcmp(s, "ignore-all-space")) + DIFF_XDL_SET(opt, IGNORE_WHITESPACE); + else if (!strcmp(s, "ignore-space-at-eol")) + DIFF_XDL_SET(opt, IGNORE_WHITESPACE_AT_EOL); + else if (!strcmp(s, "ignore-cr-at-eol")) + DIFF_XDL_SET(opt, IGNORE_CR_AT_EOL); + else if (!strcmp(s, "renormalize")) + opt->renormalize = 1; + else if (!strcmp(s, "no-renormalize")) + opt->renormalize = 0; + else if (!strcmp(s, "no-renames")) + opt->merge_detect_rename = 0; + else if (!strcmp(s, "find-renames")) { + opt->merge_detect_rename = 1; + opt->rename_score = 0; + } + else if (skip_prefix(s, "find-renames=", &arg) || + skip_prefix(s, "rename-threshold=", &arg)) { + if ((opt->rename_score = parse_rename_score(&arg)) == -1 || *arg != 0) + return -1; + opt->merge_detect_rename = 1; + } + /* + * Please update $__git_merge_strategy_options in + * git-completion.bash when you add new options + */ + else + return -1; + return 0; +} |