1 files changed, 538 insertions, 0 deletions

diff --git a/third_party/git/entry.c b/third_party/git/entry.c
new file mode 100644
index 000000000000..53380bb614c1
--- /dev/null
+++ b/third_party/git/entry.c
@@ -0,0 +1,538 @@
+#include "cache.h"
+#include "blob.h"
+#include "object-store.h"
+#include "dir.h"
+#include "streaming.h"
+#include "submodule.h"
+#include "progress.h"
+#include "fsmonitor.h"
+
+static void create_directories(const char *path, int path_len,
+			       const struct checkout *state)
+{
+	char *buf = xmallocz(path_len);
+	int len = 0;
+
+	while (len < path_len) {
+		do {
+			buf[len] = path[len];
+			len++;
+		} while (len < path_len && path[len] != '/');
+		if (len >= path_len)
+			break;
+		buf[len] = 0;
+
+		/*
+		 * For 'checkout-index --prefix=<dir>', <dir> is
+		 * allowed to be a symlink to an existing directory,
+		 * and we set 'state->base_dir_len' below, such that
+		 * we test the path components of the prefix with the
+		 * stat() function instead of the lstat() function.
+		 */
+		if (has_dirs_only_path(buf, len, state->base_dir_len))
+			continue; /* ok, it is already a directory. */
+
+		/*
+		 * If this mkdir() would fail, it could be that there
+		 * is already a symlink or something else exists
+		 * there, therefore we then try to unlink it and try
+		 * one more time to create the directory.
+		 */
+		if (mkdir(buf, 0777)) {
+			if (errno == EEXIST && state->force &&
+			    !unlink_or_warn(buf) && !mkdir(buf, 0777))
+				continue;
+			die_errno("cannot create directory at '%s'", buf);
+		}
+	}
+	free(buf);
+}
+
+static void remove_subtree(struct strbuf *path)
+{
+	DIR *dir = opendir(path->buf);
+	struct dirent *de;
+	int origlen = path->len;
+
+	if (!dir)
+		die_errno("cannot opendir '%s'", path->buf);
+	while ((de = readdir(dir)) != NULL) {
+		struct stat st;
+
+		if (is_dot_or_dotdot(de->d_name))
+			continue;
+
+		strbuf_addch(path, '/');
+		strbuf_addstr(path, de->d_name);
+		if (lstat(path->buf, &st))
+			die_errno("cannot lstat '%s'", path->buf);
+		if (S_ISDIR(st.st_mode))
+			remove_subtree(path);
+		else if (unlink(path->buf))
+			die_errno("cannot unlink '%s'", path->buf);
+		strbuf_setlen(path, origlen);
+	}
+	closedir(dir);
+	if (rmdir(path->buf))
+		die_errno("cannot rmdir '%s'", path->buf);
+}
+
+static int create_file(const char *path, unsigned int mode)
+{
+	mode = (mode & 0100) ? 0777 : 0666;
+	return open(path, O_WRONLY | O_CREAT | O_EXCL, mode);
+}
+
+static void *read_blob_entry(const struct cache_entry *ce, unsigned long *size)
+{
+	enum object_type type;
+	void *blob_data = read_object_file(&ce->oid, &type, size);
+
+	if (blob_data) {
+		if (type == OBJ_BLOB)
+			return blob_data;
+		free(blob_data);
+	}
+	return NULL;
+}
+
+static int open_output_fd(char *path, const struct cache_entry *ce, int to_tempfile)
+{
+	int symlink = (ce->ce_mode & S_IFMT) != S_IFREG;
+	if (to_tempfile) {
+		xsnprintf(path, TEMPORARY_FILENAME_LENGTH, "%s",
+			  symlink ? ".merge_link_XXXXXX" : ".merge_file_XXXXXX");
+		return mkstemp(path);
+	} else {
+		return create_file(path, !symlink ? ce->ce_mode : 0666);
+	}
+}
+
+static int fstat_output(int fd, const struct checkout *state, struct stat *st)
+{
+	/* use fstat() only when path == ce->name */
+	if (fstat_is_reliable() &&
+	    state->refresh_cache && !state->base_dir_len) {
+		fstat(fd, st);
+		return 1;
+	}
+	return 0;
+}
+
+static int streaming_write_entry(const struct cache_entry *ce, char *path,
+				 struct stream_filter *filter,
+				 const struct checkout *state, int to_tempfile,
+				 int *fstat_done, struct stat *statbuf)
+{
+	int result = 0;
+	int fd;
+
+	fd = open_output_fd(path, ce, to_tempfile);
+	if (fd < 0)
+		return -1;
+
+	result |= stream_blob_to_fd(fd, &ce->oid, filter, 1);
+	*fstat_done = fstat_output(fd, state, statbuf);
+	result |= close(fd);
+
+	if (result)
+		unlink(path);
+	return result;
+}
+
+void enable_delayed_checkout(struct checkout *state)
+{
+	if (!state->delayed_checkout) {
+		state->delayed_checkout = xmalloc(sizeof(*state->delayed_checkout));
+		state->delayed_checkout->state = CE_CAN_DELAY;
+		string_list_init(&state->delayed_checkout->filters, 0);
+		string_list_init(&state->delayed_checkout->paths, 0);
+	}
+}
+
+static int remove_available_paths(struct string_list_item *item, void *cb_data)
+{
+	struct string_list *available_paths = cb_data;
+	struct string_list_item *available;
+
+	available = string_list_lookup(available_paths, item->string);
+	if (available)
+		available->util = (void *)item->string;
+	return !available;
+}
+
+int finish_delayed_checkout(struct checkout *state, int *nr_checkouts)
+{
+	int errs = 0;
+	unsigned delayed_object_count;
+	off_t filtered_bytes = 0;
+	struct string_list_item *filter, *path;
+	struct progress *progress;
+	struct delayed_checkout *dco = state->delayed_checkout;
+
+	if (!state->delayed_checkout)
+		return errs;
+
+	dco->state = CE_RETRY;
+	delayed_object_count = dco->paths.nr;
+	progress = start_delayed_progress(_("Filtering content"), delayed_object_count);
+	while (dco->filters.nr > 0) {
+		for_each_string_list_item(filter, &dco->filters) {
+			struct string_list available_paths = STRING_LIST_INIT_NODUP;
+			display_progress(progress, delayed_object_count - dco->paths.nr);
+
+			if (!async_query_available_blobs(filter->string, &available_paths)) {
+				/* Filter reported an error */
+				errs = 1;
+				filter->string = "";
+				continue;
+			}
+			if (available_paths.nr <= 0) {
+				/*
+				 * Filter responded with no entries. That means
+				 * the filter is done and we can remove the
+				 * filter from the list (see
+				 * "string_list_remove_empty_items" call below).
+				 */
+				filter->string = "";
+				continue;
+			}
+
+			/*
+			 * In dco->paths we store a list of all delayed paths.
+			 * The filter just send us a list of available paths.
+			 * Remove them from the list.
+			 */
+			filter_string_list(&dco->paths, 0,
+				&remove_available_paths, &available_paths);
+
+			for_each_string_list_item(path, &available_paths) {
+				struct cache_entry* ce;
+
+				if (!path->util) {
+					error("external filter '%s' signaled that '%s' "
+					      "is now available although it has not been "
+					      "delayed earlier",
+					      filter->string, path->string);
+					errs |= 1;
+
+					/*
+					 * Do not ask the filter for available blobs,
+					 * again, as the filter is likely buggy.
+					 */
+					filter->string = "";
+					continue;
+				}
+				ce = index_file_exists(state->istate, path->string,
+						       strlen(path->string), 0);
+				if (ce) {
+					errs |= checkout_entry(ce, state, NULL, nr_checkouts);
+					filtered_bytes += ce->ce_stat_data.sd_size;
+					display_throughput(progress, filtered_bytes);
+				} else
+					errs = 1;
+			}
+		}
+		string_list_remove_empty_items(&dco->filters, 0);
+	}
+	stop_progress(&progress);
+	string_list_clear(&dco->filters, 0);
+
+	/* At this point we should not have any delayed paths anymore. */
+	errs |= dco->paths.nr;
+	for_each_string_list_item(path, &dco->paths) {
+		error("'%s' was not filtered properly", path->string);
+	}
+	string_list_clear(&dco->paths, 0);
+
+	free(dco);
+	state->delayed_checkout = NULL;
+
+	return errs;
+}
+
+static int write_entry(struct cache_entry *ce,
+		       char *path, const struct checkout *state, int to_tempfile)
+{
+	unsigned int ce_mode_s_ifmt = ce->ce_mode & S_IFMT;
+	struct delayed_checkout *dco = state->delayed_checkout;
+	int fd, ret, fstat_done = 0;
+	char *new_blob;
+	struct strbuf buf = STRBUF_INIT;
+	unsigned long size;
+	ssize_t wrote;
+	size_t newsize = 0;
+	struct stat st;
+	const struct submodule *sub;
+
+	if (ce_mode_s_ifmt == S_IFREG) {
+		struct stream_filter *filter = get_stream_filter(state->istate, ce->name,
+								 &ce->oid);
+		if (filter &&
+		    !streaming_write_entry(ce, path, filter,
+					   state, to_tempfile,
+					   &fstat_done, &st))
+			goto finish;
+	}
+
+	switch (ce_mode_s_ifmt) {
+	case S_IFLNK:
+		new_blob = read_blob_entry(ce, &size);
+		if (!new_blob)
+			return error("unable to read sha1 file of %s (%s)",
+				     path, oid_to_hex(&ce->oid));
+
+		/*
+		 * We can't make a real symlink; write out a regular file entry
+		 * with the symlink destination as its contents.
+		 */
+		if (!has_symlinks || to_tempfile)
+			goto write_file_entry;
+
+		ret = symlink(new_blob, path);
+		free(new_blob);
+		if (ret)
+			return error_errno("unable to create symlink %s", path);
+		break;
+
+	case S_IFREG:
+		/*
+		 * We do not send the blob in case of a retry, so do not
+		 * bother reading it at all.
+		 */
+		if (dco && dco->state == CE_RETRY) {
+			new_blob = NULL;
+			size = 0;
+		} else {
+			new_blob = read_blob_entry(ce, &size);
+			if (!new_blob)
+				return error("unable to read sha1 file of %s (%s)",
+					     path, oid_to_hex(&ce->oid));
+		}
+
+		/*
+		 * Convert from git internal format to working tree format
+		 */
+		if (dco && dco->state != CE_NO_DELAY) {
+			ret = async_convert_to_working_tree(state->istate, ce->name, new_blob,
+							    size, &buf, dco);
+			if (ret && string_list_has_string(&dco->paths, ce->name)) {
+				free(new_blob);
+				goto delayed;
+			}
+		} else
+			ret = convert_to_working_tree(state->istate, ce->name, new_blob, size, &buf);
+
+		if (ret) {
+			free(new_blob);
+			new_blob = strbuf_detach(&buf, &newsize);
+			size = newsize;
+		}
+		/*
+		 * No "else" here as errors from convert are OK at this
+		 * point. If the error would have been fatal (e.g.
+		 * filter is required), then we would have died already.
+		 */
+
+	write_file_entry:
+		fd = open_output_fd(path, ce, to_tempfile);
+		if (fd < 0) {
+			free(new_blob);
+			return error_errno("unable to create file %s", path);
+		}
+
+		wrote = write_in_full(fd, new_blob, size);
+		if (!to_tempfile)
+			fstat_done = fstat_output(fd, state, &st);
+		close(fd);
+		free(new_blob);
+		if (wrote < 0)
+			return error("unable to write file %s", path);
+		break;
+
+	case S_IFGITLINK:
+		if (to_tempfile)
+			return error("cannot create temporary submodule %s", path);
+		if (mkdir(path, 0777) < 0)
+			return error("cannot create submodule directory %s", path);
+		sub = submodule_from_ce(ce);
+		if (sub)
+			return submodule_move_head(ce->name,
+				NULL, oid_to_hex(&ce->oid),
+				state->force ? SUBMODULE_MOVE_HEAD_FORCE : 0);
+		break;
+
+	default:
+		return error("unknown file mode for %s in index", path);
+	}
+
+finish:
+	if (state->refresh_cache) {
+		assert(state->istate);
+		if (!fstat_done)
+			if (lstat(ce->name, &st) < 0)
+				return error_errno("unable to stat just-written file %s",
+						   ce->name);
+		fill_stat_cache_info(state->istate, ce, &st);
+		ce->ce_flags |= CE_UPDATE_IN_BASE;
+		mark_fsmonitor_invalid(state->istate, ce);
+		state->istate->cache_changed |= CE_ENTRY_CHANGED;
+	}
+delayed:
+	return 0;
+}
+
+/*
+ * This is like 'lstat()', except it refuses to follow symlinks
+ * in the path, after skipping "skiplen".
+ */
+static int check_path(const char *path, int len, struct stat *st, int skiplen)
+{
+	const char *slash = path + len;
+
+	while (path < slash && *slash != '/')
+		slash--;
+	if (!has_dirs_only_path(path, slash - path, skiplen)) {
+		errno = ENOENT;
+		return -1;
+	}
+	return lstat(path, st);
+}
+
+static void mark_colliding_entries(const struct checkout *state,
+				   struct cache_entry *ce, struct stat *st)
+{
+	int i, trust_ino = check_stat;
+
+#if defined(GIT_WINDOWS_NATIVE) || defined(__CYGWIN__)
+	trust_ino = 0;
+#endif
+
+	ce->ce_flags |= CE_MATCHED;
+
+	for (i = 0; i < state->istate->cache_nr; i++) {
+		struct cache_entry *dup = state->istate->cache[i];
+
+		if (dup == ce)
+			break;
+
+		if (dup->ce_flags & (CE_MATCHED | CE_VALID | CE_SKIP_WORKTREE))
+			continue;
+
+		if ((trust_ino && !match_stat_data(&dup->ce_stat_data, st)) ||
+		    (!trust_ino && !fspathcmp(ce->name, dup->name))) {
+			dup->ce_flags |= CE_MATCHED;
+			break;
+		}
+	}
+}
+
+/*
+ * Write the contents from ce out to the working tree.
+ *
+ * When topath[] is not NULL, instead of writing to the working tree
+ * file named by ce, a temporary file is created by this function and
+ * its name is returned in topath[], which must be able to hold at
+ * least TEMPORARY_FILENAME_LENGTH bytes long.
+ */
+int checkout_entry(struct cache_entry *ce, const struct checkout *state,
+		   char *topath, int *nr_checkouts)
+{
+	static struct strbuf path = STRBUF_INIT;
+	struct stat st;
+
+	if (ce->ce_flags & CE_WT_REMOVE) {
+		if (topath)
+			/*
+			 * No content and thus no path to create, so we have
+			 * no pathname to return.
+			 */
+			BUG("Can't remove entry to a path");
+		unlink_entry(ce);
+		return 0;
+	}
+
+	if (topath)
+		return write_entry(ce, topath, state, 1);
+
+	strbuf_reset(&path);
+	strbuf_add(&path, state->base_dir, state->base_dir_len);
+	strbuf_add(&path, ce->name, ce_namelen(ce));
+
+	if (!check_path(path.buf, path.len, &st, state->base_dir_len)) {
+		const struct submodule *sub;
+		unsigned changed = ie_match_stat(state->istate, ce, &st,
+						 CE_MATCH_IGNORE_VALID | CE_MATCH_IGNORE_SKIP_WORKTREE);
+		/*
+		 * Needs to be checked before !changed returns early,
+		 * as the possibly empty directory was not changed
+		 */
+		sub = submodule_from_ce(ce);
+		if (sub) {
+			int err;
+			if (!is_submodule_populated_gently(ce->name, &err)) {
+				struct stat sb;
+				if (lstat(ce->name, &sb))
+					die(_("could not stat file '%s'"), ce->name);
+				if (!(st.st_mode & S_IFDIR))
+					unlink_or_warn(ce->name);
+
+				return submodule_move_head(ce->name,
+					NULL, oid_to_hex(&ce->oid), 0);
+			} else
+				return submodule_move_head(ce->name,
+					"HEAD", oid_to_hex(&ce->oid),
+					state->force ? SUBMODULE_MOVE_HEAD_FORCE : 0);
+		}
+
+		if (!changed)
+			return 0;
+		if (!state->force) {
+			if (!state->quiet)
+				fprintf(stderr,
+					"%s already exists, no checkout\n",
+					path.buf);
+			return -1;
+		}
+
+		if (state->clone)
+			mark_colliding_entries(state, ce, &st);
+
+		/*
+		 * We unlink the old file, to get the new one with the
+		 * right permissions (including umask, which is nasty
+		 * to emulate by hand - much easier to let the system
+		 * just do the right thing)
+		 */
+		if (S_ISDIR(st.st_mode)) {
+			/* If it is a gitlink, leave it alone! */
+			if (S_ISGITLINK(ce->ce_mode))
+				return 0;
+			if (!state->force)
+				return error("%s is a directory", path.buf);
+			remove_subtree(&path);
+		} else if (unlink(path.buf))
+			return error_errno("unable to unlink old '%s'", path.buf);
+	} else if (state->not_new)
+		return 0;
+
+	create_directories(path.buf, path.len, state);
+	if (nr_checkouts)
+		(*nr_checkouts)++;
+	return write_entry(ce, path.buf, state, 0);
+}
+
+void unlink_entry(const struct cache_entry *ce)
+{
+	const struct submodule *sub = submodule_from_ce(ce);
+	if (sub) {
+		/* state.force is set at the caller. */
+		submodule_move_head(ce->name, "HEAD", NULL,
+				    SUBMODULE_MOVE_HEAD_FORCE);
+	}
+	if (!check_leading_path(ce->name, ce_namelen(ce)))
+		return;
+	if (remove_or_warn(ce->ce_mode, ce->name))
+		return;
+	schedule_dir_for_removal(ce->name, ce_namelen(ce));
+}