merge(3p/git): Merge git subtree at v2.29.2 r/1890

This also bumps the stable nixpkgs to 20.09 as of 2020-11-21, because
there is some breakage in the git build related to the netrc
credentials helper which someone has taken care of in nixpkgs.

The stable channel is not used for anything other than git, so this
should be fine.

Change-Id: I3575a19dab09e1e9556cf8231d717de9890484fb

1 files changed, 213 insertions, 200 deletions

diff --git a/third_party/git/refs.c b/third_party/git/refs.c
index cd297ee4bdbe..fa01153151a8 100644
--- a/third_party/git/refs.c
+++ b/third_party/git/refs.c
@@ -9,13 +9,15 @@
 #include "iterator.h"
 #include "refs.h"
 #include "refs/refs-internal.h"
+#include "run-command.h"
 #include "object-store.h"
 #include "object.h"
 #include "tag.h"
 #include "submodule.h"
 #include "worktree.h"
-#include "argv-array.h"
+#include "strvec.h"
 #include "repository.h"
+#include "sigchain.h"
 
 /*
  * List of all available backends
@@ -311,7 +313,7 @@ int read_ref(const char *refname, struct object_id *oid)
 	return read_ref_full(refname, RESOLVE_REF_READING, oid, NULL);
 }
 
-static int refs_ref_exists(struct ref_store *refs, const char *refname)
+int refs_ref_exists(struct ref_store *refs, const char *refname)
 {
 	return !!refs_resolve_ref_unsafe(refs, refname, RESOLVE_REF_READING, NULL, NULL);
 }
@@ -321,50 +323,6 @@ int ref_exists(const char *refname)
 	return refs_ref_exists(get_main_ref_store(the_repository), refname);
 }
 
-static int match_ref_pattern(const char *refname,
-			     const struct string_list_item *item)
-{
-	int matched = 0;
-	if (item->util == NULL) {
-		if (!wildmatch(item->string, refname, 0))
-			matched = 1;
-	} else {
-		const char *rest;
-		if (skip_prefix(refname, item->string, &rest) &&
-		    (!*rest || *rest == '/'))
-			matched = 1;
-	}
-	return matched;
-}
-
-int ref_filter_match(const char *refname,
-		     const struct string_list *include_patterns,
-		     const struct string_list *exclude_patterns)
-{
-	struct string_list_item *item;
-
-	if (exclude_patterns && exclude_patterns->nr) {
-		for_each_string_list_item(item, exclude_patterns) {
-			if (match_ref_pattern(refname, item))
-				return 0;
-		}
-	}
-
-	if (include_patterns && include_patterns->nr) {
-		int found = 0;
-		for_each_string_list_item(item, include_patterns) {
-			if (match_ref_pattern(refname, item)) {
-				found = 1;
-				break;
-			}
-		}
-
-		if (!found)
-			return 0;
-	}
-	return 1;
-}
-
 static int filter_refs(const char *refname, const struct object_id *oid,
 			   int flags, void *data)
 {
@@ -383,7 +341,7 @@ enum peel_status peel_object(const struct object_id *name, struct object_id *oid
 
 	if (o->type == OBJ_NONE) {
 		int type = oid_object_info(the_repository, name, NULL);
-		if (type < 0 || !object_as_type(the_repository, o, type, 0))
+		if (type < 0 || !object_as_type(o, type, 0))
 			return PEEL_INVALID;
 	}
 
@@ -595,13 +553,43 @@ int refname_match(const char *abbrev_name, const char *full_name)
  * Given a 'prefix' expand it by the rules in 'ref_rev_parse_rules' and add
  * the results to 'prefixes'
  */
-void expand_ref_prefix(struct argv_array *prefixes, const char *prefix)
+void expand_ref_prefix(struct strvec *prefixes, const char *prefix)
 {
 	const char **p;
 	int len = strlen(prefix);
 
 	for (p = ref_rev_parse_rules; *p; p++)
-		argv_array_pushf(prefixes, *p, len, prefix);
+		strvec_pushf(prefixes, *p, len, prefix);
+}
+
+char *repo_default_branch_name(struct repository *r)
+{
+	const char *config_key = "init.defaultbranch";
+	const char *config_display_key = "init.defaultBranch";
+	char *ret = NULL, *full_ref;
+
+	if (repo_config_get_string(r, config_key, &ret) < 0)
+		die(_("could not retrieve `%s`"), config_display_key);
+
+	if (!ret)
+		ret = xstrdup("master");
+
+	full_ref = xstrfmt("refs/heads/%s", ret);
+	if (check_refname_format(full_ref, 0))
+		die(_("invalid branch name: %s = %s"), config_display_key, ret);
+	free(full_ref);
+
+	return ret;
+}
+
+const char *git_default_branch_name(void)
+{
+	static char *ret;
+
+	if (!ret)
+		ret = repo_default_branch_name(the_repository);
+
+	return ret;
 }
 
 /*
@@ -610,10 +598,14 @@ void expand_ref_prefix(struct argv_array *prefixes, const char *prefix)
  * to name a branch.
  */
 static char *substitute_branch_name(struct repository *r,
-				    const char **string, int *len)
+				    const char **string, int *len,
+				    int nonfatal_dangling_mark)
 {
 	struct strbuf buf = STRBUF_INIT;
-	int ret = repo_interpret_branch_name(r, *string, *len, &buf, 0);
+	struct interpret_branch_name_options options = {
+		.nonfatal_dangling_mark = nonfatal_dangling_mark
+	};
+	int ret = repo_interpret_branch_name(r, *string, *len, &buf, &options);
 
 	if (ret == *len) {
 		size_t size;
@@ -626,19 +618,15 @@ static char *substitute_branch_name(struct repository *r,
 }
 
 int repo_dwim_ref(struct repository *r, const char *str, int len,
-		  struct object_id *oid, char **ref)
+		  struct object_id *oid, char **ref, int nonfatal_dangling_mark)
 {
-	char *last_branch = substitute_branch_name(r, &str, &len);
+	char *last_branch = substitute_branch_name(r, &str, &len,
+						   nonfatal_dangling_mark);
 	int   refs_found  = expand_ref(r, str, len, oid, ref);
 	free(last_branch);
 	return refs_found;
 }
 
-int dwim_ref(const char *str, int len, struct object_id *oid, char **ref)
-{
-	return repo_dwim_ref(the_repository, str, len, oid, ref);
-}
-
 int expand_ref(struct repository *repo, const char *str, int len,
 	       struct object_id *oid, char **ref)
 {
@@ -677,7 +665,7 @@ int repo_dwim_log(struct repository *r, const char *str, int len,
 		  struct object_id *oid, char **log)
 {
 	struct ref_store *refs = get_main_ref_store(r);
-	char *last_branch = substitute_branch_name(r, &str, &len);
+	char *last_branch = substitute_branch_name(r, &str, &len, 0);
 	const char **p;
 	int logs_found = 0;
 	struct strbuf path = STRBUF_INIT;
@@ -720,10 +708,9 @@ int dwim_log(const char *str, int len, struct object_id *oid, char **log)
 
 static int is_per_worktree_ref(const char *refname)
 {
-	return !strcmp(refname, "HEAD") ||
-		starts_with(refname, "refs/worktree/") ||
-		starts_with(refname, "refs/bisect/") ||
-		starts_with(refname, "refs/rewritten/");
+	return starts_with(refname, "refs/worktree/") ||
+	       starts_with(refname, "refs/bisect/") ||
+	       starts_with(refname, "refs/rewritten/");
 }
 
 static int is_pseudoref_syntax(const char *refname)
@@ -783,102 +770,6 @@ long get_files_ref_lock_timeout_ms(void)
 	return timeout_ms;
 }
 
-static int write_pseudoref(const char *pseudoref, const struct object_id *oid,
-			   const struct object_id *old_oid, struct strbuf *err)
-{
-	const char *filename;
-	int fd;
-	struct lock_file lock = LOCK_INIT;
-	struct strbuf buf = STRBUF_INIT;
-	int ret = -1;
-
-	if (!oid)
-		return 0;
-
-	strbuf_addf(&buf, "%s\n", oid_to_hex(oid));
-
-	filename = git_path("%s", pseudoref);
-	fd = hold_lock_file_for_update_timeout(&lock, filename, 0,
-					       get_files_ref_lock_timeout_ms());
-	if (fd < 0) {
-		strbuf_addf(err, _("could not open '%s' for writing: %s"),
-			    filename, strerror(errno));
-		goto done;
-	}
-
-	if (old_oid) {
-		struct object_id actual_old_oid;
-
-		if (read_ref(pseudoref, &actual_old_oid)) {
-			if (!is_null_oid(old_oid)) {
-				strbuf_addf(err, _("could not read ref '%s'"),
-					    pseudoref);
-				rollback_lock_file(&lock);
-				goto done;
-			}
-		} else if (is_null_oid(old_oid)) {
-			strbuf_addf(err, _("ref '%s' already exists"),
-				    pseudoref);
-			rollback_lock_file(&lock);
-			goto done;
-		} else if (!oideq(&actual_old_oid, old_oid)) {
-			strbuf_addf(err, _("unexpected object ID when writing '%s'"),
-				    pseudoref);
-			rollback_lock_file(&lock);
-			goto done;
-		}
-	}
-
-	if (write_in_full(fd, buf.buf, buf.len) < 0) {
-		strbuf_addf(err, _("could not write to '%s'"), filename);
-		rollback_lock_file(&lock);
-		goto done;
-	}
-
-	commit_lock_file(&lock);
-	ret = 0;
-done:
-	strbuf_release(&buf);
-	return ret;
-}
-
-static int delete_pseudoref(const char *pseudoref, const struct object_id *old_oid)
-{
-	const char *filename;
-
-	filename = git_path("%s", pseudoref);
-
-	if (old_oid && !is_null_oid(old_oid)) {
-		struct lock_file lock = LOCK_INIT;
-		int fd;
-		struct object_id actual_old_oid;
-
-		fd = hold_lock_file_for_update_timeout(
-				&lock, filename, 0,
-				get_files_ref_lock_timeout_ms());
-		if (fd < 0) {
-			error_errno(_("could not open '%s' for writing"),
-				    filename);
-			return -1;
-		}
-		if (read_ref(pseudoref, &actual_old_oid))
-			die(_("could not read ref '%s'"), pseudoref);
-		if (!oideq(&actual_old_oid, old_oid)) {
-			error(_("unexpected object ID when deleting '%s'"),
-			      pseudoref);
-			rollback_lock_file(&lock);
-			return -1;
-		}
-
-		unlink(filename);
-		rollback_lock_file(&lock);
-	} else {
-		unlink(filename);
-	}
-
-	return 0;
-}
-
 int refs_delete_ref(struct ref_store *refs, const char *msg,
 		    const char *refname,
 		    const struct object_id *old_oid,
@@ -887,11 +778,6 @@ int refs_delete_ref(struct ref_store *refs, const char *msg,
 	struct ref_transaction *transaction;
 	struct strbuf err = STRBUF_INIT;
 
-	if (ref_type(refname) == REF_TYPE_PSEUDOREF) {
-		assert(refs == get_main_ref_store(the_repository));
-		return delete_pseudoref(refname, old_oid);
-	}
-
 	transaction = ref_store_transaction_begin(refs, &err);
 	if (!transaction ||
 	    ref_transaction_delete(transaction, refname, old_oid,
@@ -914,12 +800,11 @@ int delete_ref(const char *msg, const char *refname,
 			       old_oid, flags);
 }
 
-void copy_reflog_msg(struct strbuf *sb, const char *msg)
+static void copy_reflog_msg(struct strbuf *sb, const char *msg)
 {
 	char c;
 	int wasspace = 1;
 
-	strbuf_addch(sb, '\t');
 	while ((c = *msg++)) {
 		if (wasspace && isspace(c))
 			continue;
@@ -931,6 +816,15 @@ void copy_reflog_msg(struct strbuf *sb, const char *msg)
 	strbuf_rtrim(sb);
 }
 
+static char *normalize_reflog_message(const char *msg)
+{
+	struct strbuf sb = STRBUF_INIT;
+
+	if (msg && *msg)
+		copy_reflog_msg(&sb, msg);
+	return strbuf_detach(&sb, NULL);
+}
+
 int should_autocreate_reflog(const char *refname)
 {
 	switch (log_all_ref_updates) {
@@ -1136,7 +1030,7 @@ struct ref_update *ref_transaction_add_update(
 		oidcpy(&update->new_oid, new_oid);
 	if (flags & REF_HAVE_OLD)
 		oidcpy(&update->old_oid, old_oid);
-	update->msg = xstrdup_or_null(msg);
+	update->msg = normalize_reflog_message(msg);
 	return update;
 }
 
@@ -1214,18 +1108,13 @@ int refs_update_ref(struct ref_store *refs, const char *msg,
 	struct strbuf err = STRBUF_INIT;
 	int ret = 0;
 
-	if (ref_type(refname) == REF_TYPE_PSEUDOREF) {
-		assert(refs == get_main_ref_store(the_repository));
-		ret = write_pseudoref(refname, new_oid, old_oid, &err);
-	} else {
-		t = ref_store_transaction_begin(refs, &err);
-		if (!t ||
-		    ref_transaction_update(t, refname, new_oid, old_oid,
-					   flags, msg, &err) ||
-		    ref_transaction_commit(t, &err)) {
-			ret = 1;
-			ref_transaction_free(t);
-		}
+	t = ref_store_transaction_begin(refs, &err);
+	if (!t ||
+	    ref_transaction_update(t, refname, new_oid, old_oid, flags, msg,
+				   &err) ||
+	    ref_transaction_commit(t, &err)) {
+		ret = 1;
+		ref_transaction_free(t);
 	}
 	if (ret) {
 		const char *str = _("update_ref failed for ref '%s': %s");
@@ -1638,11 +1527,37 @@ int for_each_rawref(each_ref_fn fn, void *cb_data)
 	return refs_for_each_rawref(get_main_ref_store(the_repository), fn, cb_data);
 }
 
+static int refs_read_special_head(struct ref_store *ref_store,
+				  const char *refname, struct object_id *oid,
+				  struct strbuf *referent, unsigned int *type)
+{
+	struct strbuf full_path = STRBUF_INIT;
+	struct strbuf content = STRBUF_INIT;
+	int result = -1;
+	strbuf_addf(&full_path, "%s/%s", ref_store->gitdir, refname);
+
+	if (strbuf_read_file(&content, full_path.buf, 0) < 0)
+		goto done;
+
+	result = parse_loose_ref_contents(content.buf, oid, referent, type);
+
+done:
+	strbuf_release(&full_path);
+	strbuf_release(&content);
+	return result;
+}
+
 int refs_read_raw_ref(struct ref_store *ref_store,
 		      const char *refname, struct object_id *oid,
 		      struct strbuf *referent, unsigned int *type)
 {
-	return ref_store->be->read_raw_ref(ref_store, refname, oid, referent, type);
+	if (!strcmp(refname, "FETCH_HEAD") || !strcmp(refname, "MERGE_HEAD")) {
+		return refs_read_special_head(ref_store, refname, oid, referent,
+					      type);
+	}
+
+	return ref_store->be->read_raw_ref(ref_store, refname, oid, referent,
+					   type);
 }
 
 /* This function needs to return a meaningful errno on failure */
@@ -1772,7 +1687,7 @@ int resolve_gitlink_ref(const char *submodule, const char *refname,
 
 struct ref_store_hash_entry
 {
-	struct hashmap_entry ent; /* must be the first member! */
+	struct hashmap_entry ent;
 
 	struct ref_store *refs;
 
@@ -1781,11 +1696,16 @@ struct ref_store_hash_entry
 };
 
 static int ref_store_hash_cmp(const void *unused_cmp_data,
-			      const void *entry, const void *entry_or_key,
+			      const struct hashmap_entry *eptr,
+			      const struct hashmap_entry *entry_or_key,
 			      const void *keydata)
 {
-	const struct ref_store_hash_entry *e1 = entry, *e2 = entry_or_key;
-	const char *name = keydata ? keydata : e2->name;
+	const struct ref_store_hash_entry *e1, *e2;
+	const char *name;
+
+	e1 = container_of(eptr, const struct ref_store_hash_entry, ent);
+	e2 = container_of(entry_or_key, const struct ref_store_hash_entry, ent);
+	name = keydata ? keydata : e2->name;
 
 	return strcmp(e1->name, name);
 }
@@ -1796,7 +1716,7 @@ static struct ref_store_hash_entry *alloc_ref_store_hash_entry(
 	struct ref_store_hash_entry *entry;
 
 	FLEX_ALLOC_STR(entry, name, name);
-	hashmap_entry_init(entry, strhash(name));
+	hashmap_entry_init(&entry->ent, strhash(name));
 	entry->refs = refs;
 	return entry;
 }
@@ -1815,12 +1735,15 @@ static struct ref_store *lookup_ref_store_map(struct hashmap *map,
 					      const char *name)
 {
 	struct ref_store_hash_entry *entry;
+	unsigned int hash;
 
 	if (!map->tablesize)
 		/* It's initialized on demand in register_ref_store(). */
 		return NULL;
 
-	entry = hashmap_get_from_hash(map, strhash(name), name);
+	hash = strhash(name);
+	entry = hashmap_get_entry_from_hash(map, hash, name,
+					struct ref_store_hash_entry, ent);
 	return entry ? entry->refs : NULL;
 }
 
@@ -1844,14 +1767,15 @@ static struct ref_store *ref_store_init(const char *gitdir,
 
 struct ref_store *get_main_ref_store(struct repository *r)
 {
-	if (r->refs)
-		return r->refs;
+	if (r->refs_private)
+		return r->refs_private;
 
 	if (!r->gitdir)
 		BUG("attempting to get main_ref_store outside of repository");
 
-	r->refs = ref_store_init(r->gitdir, REF_STORE_ALL_CAPS);
-	return r->refs;
+	r->refs_private = ref_store_init(r->gitdir, REF_STORE_ALL_CAPS);
+	r->refs_private = maybe_debug_wrap_ref_store(r->gitdir, r->refs_private);
+	return r->refs_private;
 }
 
 /*
@@ -1863,10 +1787,13 @@ static void register_ref_store_map(struct hashmap *map,
 				   struct ref_store *refs,
 				   const char *name)
 {
+	struct ref_store_hash_entry *entry;
+
 	if (!map->tablesize)
 		hashmap_init(map, ref_store_hash_cmp, NULL, 0);
 
-	if (hashmap_put(map, alloc_ref_store_hash_entry(name, refs)))
+	entry = alloc_ref_store_hash_entry(name, refs);
+	if (hashmap_put(map, &entry->ent))
 		BUG("%s ref_store '%s' initialized twice", type, name);
 }
 
@@ -1984,9 +1911,14 @@ int refs_create_symref(struct ref_store *refs,
 		       const char *refs_heads_master,
 		       const char *logmsg)
 {
-	return refs->be->create_symref(refs, ref_target,
-				       refs_heads_master,
-				       logmsg);
+	char *msg;
+	int retval;
+
+	msg = normalize_reflog_message(logmsg);
+	retval = refs->be->create_symref(refs, ref_target, refs_heads_master,
+					 msg);
+	free(msg);
+	return retval;
 }
 
 int create_symref(const char *ref_target, const char *refs_heads_master,
@@ -2019,10 +1951,58 @@ int ref_update_reject_duplicates(struct string_list *refnames,
 	return 0;
 }
 
+static int run_transaction_hook(struct ref_transaction *transaction,
+				const char *state)
+{
+	struct child_process proc = CHILD_PROCESS_INIT;
+	struct strbuf buf = STRBUF_INIT;
+	const char *hook;
+	int ret = 0, i;
+
+	hook = find_hook("reference-transaction");
+	if (!hook)
+		return ret;
+
+	strvec_pushl(&proc.args, hook, state, NULL);
+	proc.in = -1;
+	proc.stdout_to_stderr = 1;
+	proc.trace2_hook_name = "reference-transaction";
+
+	ret = start_command(&proc);
+	if (ret)
+		return ret;
+
+	sigchain_push(SIGPIPE, SIG_IGN);
+
+	for (i = 0; i < transaction->nr; i++) {
+		struct ref_update *update = transaction->updates[i];
+
+		strbuf_reset(&buf);
+		strbuf_addf(&buf, "%s %s %s\n",
+			    oid_to_hex(&update->old_oid),
+			    oid_to_hex(&update->new_oid),
+			    update->refname);
+
+		if (write_in_full(proc.in, buf.buf, buf.len) < 0) {
+			if (errno != EPIPE)
+				ret = -1;
+			break;
+		}
+	}
+
+	close(proc.in);
+	sigchain_pop(SIGPIPE);
+	strbuf_release(&buf);
+
+	ret |= finish_command(&proc);
+	return ret;
+}
+
 int ref_transaction_prepare(struct ref_transaction *transaction,
 			    struct strbuf *err)
 {
 	struct ref_store *refs = transaction->ref_store;
+	int ret;
 
 	switch (transaction->state) {
 	case REF_TRANSACTION_OPEN:
@@ -2045,7 +2025,17 @@ int ref_transaction_prepare(struct ref_transaction *transaction,
 		return -1;
 	}
 
-	return refs->be->transaction_prepare(refs, transaction, err);
+	ret = refs->be->transaction_prepare(refs, transaction, err);
+	if (ret)
+		return ret;
+
+	ret = run_transaction_hook(transaction, "prepared");
+	if (ret) {
+		ref_transaction_abort(transaction, err);
+		die(_("ref updates aborted by hook"));
+	}
+
+	return 0;
 }
 
 int ref_transaction_abort(struct ref_transaction *transaction,
@@ -2069,6 +2059,8 @@ int ref_transaction_abort(struct ref_transaction *transaction,
 		break;
 	}
 
+	run_transaction_hook(transaction, "aborted");
+
 	ref_transaction_free(transaction);
 	return ret;
 }
@@ -2097,7 +2089,10 @@ int ref_transaction_commit(struct ref_transaction *transaction,
 		break;
 	}
 
-	return refs->be->transaction_finish(refs, transaction, err);
+	ret = refs->be->transaction_finish(refs, transaction, err);
+	if (!ret)
+		run_transaction_hook(transaction, "committed");
+	return ret;
 }
 
 int refs_verify_refname_available(struct ref_store *refs,
@@ -2301,10 +2296,16 @@ int initial_ref_transaction_commit(struct ref_transaction *transaction,
 	return refs->be->initial_transaction_commit(refs, transaction, err);
 }
 
-int refs_delete_refs(struct ref_store *refs, const char *msg,
+int refs_delete_refs(struct ref_store *refs, const char *logmsg,
 		     struct string_list *refnames, unsigned int flags)
 {
-	return refs->be->delete_refs(refs, msg, refnames, flags);
+	char *msg;
+	int retval;
+
+	msg = normalize_reflog_message(logmsg);
+	retval = refs->be->delete_refs(refs, msg, refnames, flags);
+	free(msg);
+	return retval;
 }
 
 int delete_refs(const char *msg, struct string_list *refnames,
@@ -2316,7 +2317,13 @@ int delete_refs(const char *msg, struct string_list *refnames,
 int refs_rename_ref(struct ref_store *refs, const char *oldref,
 		    const char *newref, const char *logmsg)
 {
-	return refs->be->rename_ref(refs, oldref, newref, logmsg);
+	char *msg;
+	int retval;
+
+	msg = normalize_reflog_message(logmsg);
+	retval = refs->be->rename_ref(refs, oldref, newref, msg);
+	free(msg);
+	return retval;
 }
 
 int rename_ref(const char *oldref, const char *newref, const char *logmsg)
@@ -2327,7 +2334,13 @@ int rename_ref(const char *oldref, const char *newref, const char *logmsg)
 int refs_copy_existing_ref(struct ref_store *refs, const char *oldref,
 		    const char *newref, const char *logmsg)
 {
-	return refs->be->copy_ref(refs, oldref, newref, logmsg);
+	char *msg;
+	int retval;
+
+	msg = normalize_reflog_message(logmsg);
+	retval = refs->be->copy_ref(refs, oldref, newref, msg);
+	free(msg);
+	return retval;
 }
 
 int copy_existing_ref(const char *oldref, const char *newref, const char *logmsg)