1 files changed, 101 insertions, 71 deletions

diff --git a/refs.c b/refs.c
index 7f019c2377..4338875d86 100644
--- a/refs.c
+++ b/refs.c
@@ -251,12 +251,13 @@ int refname_is_safe(const char *refname)
  * does not exist, emit a warning and return false.
  */
 int ref_resolves_to_object(const char *refname,
+			   struct repository *repo,
 			   const struct object_id *oid,
 			   unsigned int flags)
 {
 	if (flags & REF_ISBROKEN)
 		return 0;
-	if (!has_object_file(oid)) {
+	if (!repo_has_object_file(repo, oid)) {
 		error(_("%s does not point to a valid object!"), refname);
 		return 0;
 	}
@@ -268,9 +269,10 @@ char *refs_resolve_refdup(struct ref_store *refs,
 			  struct object_id *oid, int *flags)
 {
 	const char *result;
+	int ignore_errno;
 
 	result = refs_resolve_ref_unsafe(refs, refname, resolve_flags,
-					 oid, flags);
+					 oid, flags, &ignore_errno);
 	return xstrdup_or_null(result);
 }
 
@@ -290,20 +292,17 @@ struct ref_filter {
 	void *cb_data;
 };
 
-int refs_read_ref_full(struct ref_store *refs, const char *refname,
-		       int resolve_flags, struct object_id *oid, int *flags)
+int read_ref_full(const char *refname, int resolve_flags, struct object_id *oid, int *flags)
 {
-	if (refs_resolve_ref_unsafe(refs, refname, resolve_flags, oid, flags))
+	int ignore_errno;
+	struct ref_store *refs = get_main_ref_store(the_repository);
+
+	if (refs_resolve_ref_unsafe(refs, refname, resolve_flags,
+				    oid, flags, &ignore_errno))
 		return 0;
 	return -1;
 }
 
-int read_ref_full(const char *refname, int resolve_flags, struct object_id *oid, int *flags)
-{
-	return refs_read_ref_full(get_main_ref_store(the_repository), refname,
-				  resolve_flags, oid, flags);
-}
-
 int read_ref(const char *refname, struct object_id *oid)
 {
 	return read_ref_full(refname, RESOLVE_REF_READING, oid, NULL);
@@ -311,7 +310,9 @@ int read_ref(const char *refname, struct object_id *oid)
 
 int refs_ref_exists(struct ref_store *refs, const char *refname)
 {
-	return !!refs_resolve_ref_unsafe(refs, refname, RESOLVE_REF_READING, NULL, NULL);
+	int ignore_errno;
+	return !!refs_resolve_ref_unsafe(refs, refname, RESOLVE_REF_READING,
+					 NULL, NULL, &ignore_errno);
 }
 
 int ref_exists(const char *refname)
@@ -654,13 +655,16 @@ int expand_ref(struct repository *repo, const char *str, int len,
 		struct object_id oid_from_ref;
 		struct object_id *this_result;
 		int flag;
+		struct ref_store *refs = get_main_ref_store(repo);
+		int ignore_errno;
 
 		this_result = refs_found ? &oid_from_ref : oid;
 		strbuf_reset(&fullref);
 		strbuf_addf(&fullref, *p, len, str);
-		r = refs_resolve_ref_unsafe(get_main_ref_store(repo),
-					    fullref.buf, RESOLVE_REF_READING,
-					    this_result, &flag);
+		r = refs_resolve_ref_unsafe(refs, fullref.buf,
+					    RESOLVE_REF_READING,
+					    this_result, &flag,
+					    &ignore_errno);
 		if (r) {
 			if (!refs_found++)
 				*ref = xstrdup(r);
@@ -689,12 +693,14 @@ int repo_dwim_log(struct repository *r, const char *str, int len,
 	for (p = ref_rev_parse_rules; *p; p++) {
 		struct object_id hash;
 		const char *ref, *it;
+		int ignore_errno;
 
 		strbuf_reset(&path);
 		strbuf_addf(&path, *p, len, str);
 		ref = refs_resolve_ref_unsafe(refs, path.buf,
 					      RESOLVE_REF_READING,
-					      oid ? &hash : NULL, NULL);
+					      oid ? &hash : NULL, NULL,
+					      &ignore_errno);
 		if (!ref)
 			continue;
 		if (refs_reflog_exists(refs, path.buf))
@@ -1088,6 +1094,13 @@ int ref_transaction_update(struct ref_transaction *transaction,
 	if (flags & ~REF_TRANSACTION_UPDATE_ALLOWED_FLAGS)
 		BUG("illegal flags 0x%x passed to ref_transaction_update()", flags);
 
+	/*
+	 * Clear flags outside the allowed set; this should be a noop because
+	 * of the BUG() check above, but it works around a -Wnonnull warning
+	 * with some versions of "gcc -O3".
+	 */
+	flags &= REF_TRANSACTION_UPDATE_ALLOWED_FLAGS;
+
 	flags |= (new_oid ? REF_HAVE_NEW : 0) | (old_oid ? REF_HAVE_OLD : 0);
 
 	ref_transaction_add_update(transaction, refname, flags,
@@ -1372,32 +1385,14 @@ const char *find_descendant_ref(const char *dirname,
 	return NULL;
 }
 
-int refs_rename_ref_available(struct ref_store *refs,
-			      const char *old_refname,
-			      const char *new_refname)
-{
-	struct string_list skip = STRING_LIST_INIT_NODUP;
-	struct strbuf err = STRBUF_INIT;
-	int ok;
-
-	string_list_insert(&skip, old_refname);
-	ok = !refs_verify_refname_available(refs, new_refname,
-					    NULL, &skip, &err);
-	if (!ok)
-		error("%s", err.buf);
-
-	string_list_clear(&skip, 0);
-	strbuf_release(&err);
-	return ok;
-}
-
 int refs_head_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
 {
 	struct object_id oid;
 	int flag;
+	int ignore_errno;
 
-	if (!refs_read_ref_full(refs, "HEAD", RESOLVE_REF_READING,
-				&oid, &flag))
+	if (refs_resolve_ref_unsafe(refs, "HEAD", RESOLVE_REF_READING,
+				    &oid, &flag, &ignore_errno))
 		return fn("HEAD", &oid, flag, cb_data);
 
 	return 0;
@@ -1648,7 +1643,8 @@ int for_each_fullref_in_prefixes(const char *namespace,
 
 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 *referent, unsigned int *type,
+				  int *failure_errno)
 {
 	struct strbuf full_path = STRBUF_INIT;
 	struct strbuf content = STRBUF_INIT;
@@ -1658,7 +1654,8 @@ static int refs_read_special_head(struct ref_store *ref_store,
 	if (strbuf_read_file(&content, full_path.buf, 0) < 0)
 		goto done;
 
-	result = parse_loose_ref_contents(content.buf, oid, referent, type);
+	result = parse_loose_ref_contents(content.buf, oid, referent, type,
+					  failure_errno);
 
 done:
 	strbuf_release(&full_path);
@@ -1666,30 +1663,33 @@ done:
 	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)
+int refs_read_raw_ref(struct ref_store *ref_store, const char *refname,
+		      struct object_id *oid, struct strbuf *referent,
+		      unsigned int *type, int *failure_errno)
 {
+	assert(failure_errno);
 	if (!strcmp(refname, "FETCH_HEAD") || !strcmp(refname, "MERGE_HEAD")) {
 		return refs_read_special_head(ref_store, refname, oid, referent,
-					      type);
+					      type, failure_errno);
 	}
 
 	return ref_store->be->read_raw_ref(ref_store, refname, oid, referent,
-					   type, &errno);
+					   type, failure_errno);
 }
 
-/* This function needs to return a meaningful errno on failure */
 const char *refs_resolve_ref_unsafe(struct ref_store *refs,
 				    const char *refname,
 				    int resolve_flags,
-				    struct object_id *oid, int *flags)
+				    struct object_id *oid,
+				    int *flags, int *failure_errno)
 {
 	static struct strbuf sb_refname = STRBUF_INIT;
 	struct object_id unused_oid;
 	int unused_flags;
 	int symref_count;
 
+	assert(failure_errno);
+
 	if (!oid)
 		oid = &unused_oid;
 	if (!flags)
@@ -1700,7 +1700,7 @@ const char *refs_resolve_ref_unsafe(struct ref_store *refs,
 	if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
 		if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
 		    !refname_is_safe(refname)) {
-			errno = EINVAL;
+			*failure_errno = EINVAL;
 			return NULL;
 		}
 
@@ -1718,9 +1718,11 @@ const char *refs_resolve_ref_unsafe(struct ref_store *refs,
 	for (symref_count = 0; symref_count < SYMREF_MAXDEPTH; symref_count++) {
 		unsigned int read_flags = 0;
 
-		if (refs_read_raw_ref(refs, refname,
-				      oid, &sb_refname, &read_flags)) {
+		if (refs_read_raw_ref(refs, refname, oid, &sb_refname,
+				      &read_flags, failure_errno)) {
 			*flags |= read_flags;
+			if (errno)
+				*failure_errno = errno;
 
 			/* In reading mode, refs must eventually resolve */
 			if (resolve_flags & RESOLVE_REF_READING)
@@ -1731,9 +1733,9 @@ const char *refs_resolve_ref_unsafe(struct ref_store *refs,
 			 * may show errors besides ENOENT if there are
 			 * similarly-named refs.
 			 */
-			if (errno != ENOENT &&
-			    errno != EISDIR &&
-			    errno != ENOTDIR)
+			if (*failure_errno != ENOENT &&
+			    *failure_errno != EISDIR &&
+			    *failure_errno != ENOTDIR)
 				return NULL;
 
 			oidclr(oid);
@@ -1760,7 +1762,7 @@ const char *refs_resolve_ref_unsafe(struct ref_store *refs,
 		if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
 			if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
 			    !refname_is_safe(refname)) {
-				errno = EINVAL;
+				*failure_errno = EINVAL;
 				return NULL;
 			}
 
@@ -1768,7 +1770,7 @@ const char *refs_resolve_ref_unsafe(struct ref_store *refs,
 		}
 	}
 
-	errno = ELOOP;
+	*failure_errno = ELOOP;
 	return NULL;
 }
 
@@ -1783,8 +1785,10 @@ int refs_init_db(struct strbuf *err)
 const char *resolve_ref_unsafe(const char *refname, int resolve_flags,
 			       struct object_id *oid, int *flags)
 {
+	int ignore_errno;
+
 	return refs_resolve_ref_unsafe(get_main_ref_store(the_repository), refname,
-				       resolve_flags, oid, flags);
+				       resolve_flags, oid, flags, &ignore_errno);
 }
 
 int resolve_gitlink_ref(const char *submodule, const char *refname,
@@ -1792,14 +1796,15 @@ int resolve_gitlink_ref(const char *submodule, const char *refname,
 {
 	struct ref_store *refs;
 	int flags;
+	int ignore_errno;
 
 	refs = get_submodule_ref_store(submodule);
 
 	if (!refs)
 		return -1;
 
-	if (!refs_resolve_ref_unsafe(refs, refname, 0, oid, &flags) ||
-	    is_null_oid(oid))
+	if (!refs_resolve_ref_unsafe(refs, refname, 0, oid, &flags,
+				     &ignore_errno) || is_null_oid(oid))
 		return -1;
 	return 0;
 }
@@ -1870,7 +1875,8 @@ static struct ref_store *lookup_ref_store_map(struct hashmap *map,
  * Create, record, and return a ref_store instance for the specified
  * gitdir.
  */
-static struct ref_store *ref_store_init(const char *gitdir,
+static struct ref_store *ref_store_init(struct repository *repo,
+					const char *gitdir,
 					unsigned int flags)
 {
 	const char *be_name = "files";
@@ -1880,7 +1886,7 @@ static struct ref_store *ref_store_init(const char *gitdir,
 	if (!be)
 		BUG("reference backend %s is unknown", be_name);
 
-	refs = be->init(gitdir, flags);
+	refs = be->init(repo, gitdir, flags);
 	return refs;
 }
 
@@ -1892,7 +1898,7 @@ struct ref_store *get_main_ref_store(struct repository *r)
 	if (!r->gitdir)
 		BUG("attempting to get main_ref_store outside of repository");
 
-	r->refs_private = ref_store_init(r->gitdir, REF_STORE_ALL_CAPS);
+	r->refs_private = ref_store_init(r, r->gitdir, REF_STORE_ALL_CAPS);
 	r->refs_private = maybe_debug_wrap_ref_store(r->gitdir, r->refs_private);
 	return r->refs_private;
 }
@@ -1922,6 +1928,7 @@ struct ref_store *get_submodule_ref_store(const char *submodule)
 	struct ref_store *refs;
 	char *to_free = NULL;
 	size_t len;
+	struct repository *subrepo;
 
 	if (!submodule)
 		return NULL;
@@ -1947,8 +1954,19 @@ struct ref_store *get_submodule_ref_store(const char *submodule)
 	if (submodule_to_gitdir(&submodule_sb, submodule))
 		goto done;
 
-	/* assume that add_submodule_odb() has been called */
-	refs = ref_store_init(submodule_sb.buf,
+	subrepo = xmalloc(sizeof(*subrepo));
+	/*
+	 * NEEDSWORK: Make get_submodule_ref_store() work with arbitrary
+	 * superprojects other than the_repository. This probably should be
+	 * done by making it take a struct repository * parameter instead of a
+	 * submodule path.
+	 */
+	if (repo_submodule_init(subrepo, the_repository, submodule,
+				null_oid())) {
+		free(subrepo);
+		goto done;
+	}
+	refs = ref_store_init(subrepo, submodule_sb.buf,
 			      REF_STORE_READ | REF_STORE_ODB);
 	register_ref_store_map(&submodule_ref_stores, "submodule",
 			       refs, submodule);
@@ -1974,10 +1992,12 @@ struct ref_store *get_worktree_ref_store(const struct worktree *wt)
 		return refs;
 
 	if (wt->id)
-		refs = ref_store_init(git_common_path("worktrees/%s", wt->id),
+		refs = ref_store_init(the_repository,
+				      git_common_path("worktrees/%s", wt->id),
 				      REF_STORE_ALL_CAPS);
 	else
-		refs = ref_store_init(get_git_common_dir(),
+		refs = ref_store_init(the_repository,
+				      get_git_common_dir(),
 				      REF_STORE_ALL_CAPS);
 
 	if (refs)
@@ -2086,8 +2106,11 @@ static int run_transaction_hook(struct ref_transaction *transaction,
 			    update->refname);
 
 		if (write_in_full(proc.in, buf.buf, buf.len) < 0) {
-			if (errno != EPIPE)
+			if (errno != EPIPE) {
+				/* Don't leak errno outside this API */
+				errno = 0;
 				ret = -1;
+			}
 			break;
 		}
 	}
@@ -2222,6 +2245,13 @@ int refs_verify_refname_available(struct ref_store *refs,
 
 	strbuf_grow(&dirname, strlen(refname) + 1);
 	for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
+		/*
+		 * Just saying "Is a directory" when we e.g. can't
+		 * lock some multi-level ref isn't very informative,
+		 * the user won't be told *what* is a directory, so
+		 * let's not use strerror() below.
+		 */
+		int ignore_errno;
 		/* Expand dirname to the new prefix, not including the trailing slash: */
 		strbuf_add(&dirname, refname + dirname.len, slash - refname - dirname.len);
 
@@ -2233,7 +2263,8 @@ int refs_verify_refname_available(struct ref_store *refs,
 		if (skip && string_list_has_string(skip, dirname.buf))
 			continue;
 
-		if (!refs_read_raw_ref(refs, dirname.buf, &oid, &referent, &type)) {
+		if (!refs_read_raw_ref(refs, dirname.buf, &oid, &referent,
+				       &type, &ignore_errno)) {
 			strbuf_addf(err, _("'%s' exists; cannot create '%s'"),
 				    dirname.buf, refname);
 			goto cleanup;
@@ -2342,16 +2373,15 @@ int reflog_exists(const char *refname)
 }
 
 int refs_create_reflog(struct ref_store *refs, const char *refname,
-		       int force_create, struct strbuf *err)
+		       struct strbuf *err)
 {
-	return refs->be->create_reflog(refs, refname, force_create, err);
+	return refs->be->create_reflog(refs, refname, err);
 }
 
-int safe_create_reflog(const char *refname, int force_create,
-		       struct strbuf *err)
+int safe_create_reflog(const char *refname, struct strbuf *err)
 {
 	return refs_create_reflog(get_main_ref_store(the_repository), refname,
-				  force_create, err);
+				  err);
 }
 
 int refs_delete_reflog(struct ref_store *refs, const char *refname)