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, 42 insertions, 45 deletions

diff --git a/third_party/git/refs/files-backend.c b/third_party/git/refs/files-backend.c
index d60767ab739f..04e85e70029b 100644
--- a/third_party/git/refs/files-backend.c
+++ b/third_party/git/refs/files-backend.c
@@ -39,13 +39,6 @@
 #define REF_NEEDS_COMMIT (1 << 6)
 
 /*
- * Used as a flag in ref_update::flags when we want to log a ref
- * update but not actually perform it.  This is used when a symbolic
- * ref update is split up.
- */
-#define REF_LOG_ONLY (1 << 7)
-
-/*
  * Used as a flag in ref_update::flags when the ref_update was via an
  * update to HEAD.
  */
@@ -67,7 +60,6 @@ struct files_ref_store {
 	struct ref_store base;
 	unsigned int store_flags;
 
-	char *gitdir;
 	char *gitcommondir;
 
 	struct ref_cache *loose;
@@ -94,18 +86,17 @@ static struct ref_store *files_ref_store_create(const char *gitdir,
 	struct ref_store *ref_store = (struct ref_store *)refs;
 	struct strbuf sb = STRBUF_INIT;
 
+	ref_store->gitdir = xstrdup(gitdir);
 	base_ref_store_init(ref_store, &refs_be_files);
 	refs->store_flags = flags;
 
-	refs->gitdir = xstrdup(gitdir);
 	get_common_dir_noenv(&sb, gitdir);
 	refs->gitcommondir = strbuf_detach(&sb, NULL);
 	strbuf_addf(&sb, "%s/packed-refs", refs->gitcommondir);
 	refs->packed_ref_store = packed_ref_store_create(sb.buf, flags);
 	strbuf_release(&sb);
 
-	chdir_notify_reparent("files-backend $GIT_DIR",
-			      &refs->gitdir);
+	chdir_notify_reparent("files-backend $GIT_DIR", &refs->base.gitdir);
 	chdir_notify_reparent("files-backend $GIT_COMMONDIR",
 			      &refs->gitcommondir);
 
@@ -176,7 +167,7 @@ static void files_reflog_path(struct files_ref_store *refs,
 	switch (ref_type(refname)) {
 	case REF_TYPE_PER_WORKTREE:
 	case REF_TYPE_PSEUDOREF:
-		strbuf_addf(sb, "%s/logs/%s", refs->gitdir, refname);
+		strbuf_addf(sb, "%s/logs/%s", refs->base.gitdir, refname);
 		break;
 	case REF_TYPE_OTHER_PSEUDOREF:
 	case REF_TYPE_MAIN_PSEUDOREF:
@@ -198,7 +189,7 @@ static void files_ref_path(struct files_ref_store *refs,
 	switch (ref_type(refname)) {
 	case REF_TYPE_PER_WORKTREE:
 	case REF_TYPE_PSEUDOREF:
-		strbuf_addf(sb, "%s/%s", refs->gitdir, refname);
+		strbuf_addf(sb, "%s/%s", refs->base.gitdir, refname);
 		break;
 	case REF_TYPE_MAIN_PSEUDOREF:
 		if (!skip_prefix(refname, "main-worktree/", &refname))
@@ -360,7 +351,6 @@ static int files_read_raw_ref(struct ref_store *ref_store,
 	struct strbuf sb_path = STRBUF_INIT;
 	const char *path;
 	const char *buf;
-	const char *p;
 	struct stat st;
 	int fd;
 	int ret = -1;
@@ -465,37 +455,41 @@ stat_ref:
 	close(fd);
 	strbuf_rtrim(&sb_contents);
 	buf = sb_contents.buf;
-	if (starts_with(buf, "ref:")) {
-		buf += 4;
+
+	ret = parse_loose_ref_contents(buf, oid, referent, type);
+
+out:
+	save_errno = errno;
+	strbuf_release(&sb_path);
+	strbuf_release(&sb_contents);
+	errno = save_errno;
+	return ret;
+}
+
+int parse_loose_ref_contents(const char *buf, struct object_id *oid,
+			     struct strbuf *referent, unsigned int *type)
+{
+	const char *p;
+	if (skip_prefix(buf, "ref:", &buf)) {
 		while (isspace(*buf))
 			buf++;
 
 		strbuf_reset(referent);
 		strbuf_addstr(referent, buf);
 		*type |= REF_ISSYMREF;
-		ret = 0;
-		goto out;
+		return 0;
 	}
 
 	/*
-	 * Please note that FETCH_HEAD has additional
-	 * data after the sha.
+	 * FETCH_HEAD has additional data after the sha.
 	 */
 	if (parse_oid_hex(buf, oid, &p) ||
 	    (*p != '\0' && !isspace(*p))) {
 		*type |= REF_ISBROKEN;
 		errno = EINVAL;
-		goto out;
+		return -1;
 	}
-
-	ret = 0;
-
-out:
-	save_errno = errno;
-	strbuf_release(&sb_path);
-	strbuf_release(&sb_contents);
-	errno = save_errno;
-	return ret;
+	return 0;
 }
 
 static void unlock_ref(struct ref_lock *lock)
@@ -1327,7 +1321,7 @@ static int files_copy_or_rename_ref(struct ref_store *ref_store,
 {
 	struct files_ref_store *refs =
 		files_downcast(ref_store, REF_STORE_WRITE, "rename_ref");
-	struct object_id oid, orig_oid;
+	struct object_id orig_oid;
 	int flag = 0, logmoved = 0;
 	struct ref_lock *lock;
 	struct stat loginfo;
@@ -1395,7 +1389,7 @@ static int files_copy_or_rename_ref(struct ref_store *ref_store,
 	 */
 	if (!copy && !refs_read_ref_full(&refs->base, newrefname,
 				RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,
-				&oid, NULL) &&
+				NULL, NULL) &&
 	    refs_delete_ref(&refs->base, NULL, newrefname,
 			    NULL, REF_NO_DEREF)) {
 		if (errno == EISDIR) {
@@ -1629,8 +1623,10 @@ static int log_ref_write_fd(int fd, const struct object_id *old_oid,
 	int ret = 0;
 
 	strbuf_addf(&sb, "%s %s %s", oid_to_hex(old_oid), oid_to_hex(new_oid), committer);
-	if (msg && *msg)
-		copy_reflog_msg(&sb, msg);
+	if (msg && *msg) {
+		strbuf_addch(&sb, '\t');
+		strbuf_addstr(&sb, msg);
+	}
 	strbuf_addch(&sb, '\n');
 	if (write_in_full(fd, sb.buf, sb.len) < 0)
 		ret = -1;
@@ -2198,12 +2194,11 @@ static struct ref_iterator *files_reflog_iterator_begin(struct ref_store *ref_st
 		files_downcast(ref_store, REF_STORE_READ,
 			       "reflog_iterator_begin");
 
-	if (!strcmp(refs->gitdir, refs->gitcommondir)) {
+	if (!strcmp(refs->base.gitdir, refs->gitcommondir)) {
 		return reflog_iterator_begin(ref_store, refs->gitcommondir);
 	} else {
 		return merge_ref_iterator_begin(
-			0,
-			reflog_iterator_begin(ref_store, refs->gitdir),
+			0, reflog_iterator_begin(ref_store, refs->base.gitdir),
 			reflog_iterator_begin(ref_store, refs->gitcommondir),
 			reflog_iterator_select, refs);
 	}
@@ -2566,16 +2561,18 @@ static void files_transaction_cleanup(struct files_ref_store *refs,
 		}
 	}
 
-	if (backend_data->packed_transaction &&
-	    ref_transaction_abort(backend_data->packed_transaction, &err)) {
-		error("error aborting transaction: %s", err.buf);
-		strbuf_release(&err);
-	}
+	if (backend_data) {
+		if (backend_data->packed_transaction &&
+		    ref_transaction_abort(backend_data->packed_transaction, &err)) {
+			error("error aborting transaction: %s", err.buf);
+			strbuf_release(&err);
+		}
 
-	if (backend_data->packed_refs_locked)
-		packed_refs_unlock(refs->packed_ref_store);
+		if (backend_data->packed_refs_locked)
+			packed_refs_unlock(refs->packed_ref_store);
 
-	free(backend_data);
+		free(backend_data);
+	}
 
 	transaction->state = REF_TRANSACTION_CLOSED;
 }