refs.c: change resolve_ref_unsafe reading argument to be a flags field

rsahlberg · gitster · commit 7695d118e5a3 · 2014-10-15T10:47:24.000-07:00
resolve_ref_unsafe takes a boolean argument for reading (a nonexistent ref
resolves successfully for writing but not for reading).  Change this to be
a flags field instead, and pass the new constant RESOLVE_REF_READING when
we want this behaviour.

While at it, swap two of the arguments in the function to put output
arguments at the end.  As a nice side effect, this ensures that we can
catch callers that were unaware of the new API so they can be audited.

Give the wrapper functions resolve_refdup and read_ref_full the same
treatment for consistency.

Signed-off-by: Ronnie Sahlberg &lt;sahlberg@google.com&gt;
Signed-off-by: Jonathan Nieder &lt;jrnieder@gmail.com&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
diff --git a/branch.c b/branch.c
@@ -170,7 +170,7 @@ int validate_new_branchname(const char *name, struct strbuf *ref,
 		const char *head;
 		unsigned char sha1[20];
 
-		head = resolve_ref_unsafe("HEAD", sha1, 0, NULL);
+		head = resolve_ref_unsafe("HEAD", 0, sha1, NULL);
 		if (!is_bare_repository() && head && !strcmp(head, ref->buf))
 			die(_("Cannot force update the current branch."));
 	}
diff --git a/builtin/blame.c b/builtin/blame.c
@@ -2286,7 +2286,7 @@ static struct commit *fake_working_tree_commit(struct diff_options *opt,
 	commit->date = now;
 	parent_tail = &commit->parents;
 
-	if (!resolve_ref_unsafe("HEAD", head_sha1, 1, NULL))
+	if (!resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, head_sha1, NULL))
 		die("no such ref: HEAD");
 
 	parent_tail = append_parent(parent_tail, head_sha1);
diff --git a/builtin/branch.c b/builtin/branch.c
@@ -131,7 +131,8 @@ static int branch_merged(int kind, const char *name,
 		    branch->merge[0] &&
 		    branch->merge[0]->dst &&
 		    (reference_name = reference_name_to_free =
-		     resolve_refdup(branch->merge[0]->dst, sha1, 1, NULL)) != NULL)
+		     resolve_refdup(branch->merge[0]->dst, RESOLVE_REF_READING,
+				    sha1, NULL)) != NULL)
 			reference_rev = lookup_commit_reference(sha1);
 	}
 	if (!reference_rev)
@@ -235,7 +236,7 @@ static int delete_branches(int argc, const char **argv, int force, int kinds,
 		free(name);
 
 		name = mkpathdup(fmt, bname.buf);
-		target = resolve_ref_unsafe(name, sha1, 0, &flags);
+		target = resolve_ref_unsafe(name, 0, sha1, &flags);
 		if (!target ||
 		    (!(flags & REF_ISSYMREF) && is_null_sha1(sha1))) {
 			error(remote_branch
@@ -299,7 +300,7 @@ static char *resolve_symref(const char *src, const char *prefix)
 	int flag;
 	const char *dst;
 
-	dst = resolve_ref_unsafe(src, sha1, 0, &flag);
+	dst = resolve_ref_unsafe(src, 0, sha1, &flag);
 	if (!(dst && (flag & REF_ISSYMREF)))
 		return NULL;
 	if (prefix)
@@ -869,7 +870,7 @@ int cmd_branch(int argc, const char **argv, const char *prefix)
 
 	track = git_branch_track;
 
-	head = resolve_refdup("HEAD", head_sha1, 0, NULL);
+	head = resolve_refdup("HEAD", 0, head_sha1, NULL);
 	if (!head)
 		die(_("Failed to resolve HEAD as a valid ref."));
 	if (!strcmp(head, "HEAD"))
diff --git a/builtin/checkout.c b/builtin/checkout.c
@@ -355,7 +355,7 @@ static int checkout_paths(const struct checkout_opts *opts,
 	if (write_locked_index(&the_index, lock_file, COMMIT_LOCK))
 		die(_("unable to write new index file"));
 
-	read_ref_full("HEAD", rev, 0, &flag);
+	read_ref_full("HEAD", 0, rev, &flag);
 	head = lookup_commit_reference_gently(rev, 1);
 
 	errs |= post_checkout_hook(head, head, 0);
@@ -775,7 +775,7 @@ static int switch_branches(const struct checkout_opts *opts,
 	unsigned char rev[20];
 	int flag, writeout_error = 0;
 	memset(&old, 0, sizeof(old));
-	old.path = path_to_free = resolve_refdup("HEAD", rev, 0, &flag);
+	old.path = path_to_free = resolve_refdup("HEAD", 0, rev, &flag);
 	old.commit = lookup_commit_reference_gently(rev, 1);
 	if (!(flag & REF_ISSYMREF))
 		old.path = NULL;
@@ -1072,7 +1072,7 @@ static int checkout_branch(struct checkout_opts *opts,
 		unsigned char rev[20];
 		int flag;
 
-		if (!read_ref_full("HEAD", rev, 0, &flag) &&
+		if (!read_ref_full("HEAD", 0, rev, &flag) &&
 		    (flag & REF_ISSYMREF) && is_null_sha1(rev))
 			return switch_unborn_to_new_branch(opts);
 	}
diff --git a/builtin/clone.c b/builtin/clone.c
@@ -623,7 +623,7 @@ static int checkout(void)
 	if (option_no_checkout)
 		return 0;
 
-	head = resolve_refdup("HEAD", sha1, 1, NULL);
+	head = resolve_refdup("HEAD", RESOLVE_REF_READING, sha1, NULL);
 	if (!head) {
 		warning(_("remote HEAD refers to nonexistent ref, "
 			  "unable to checkout.\n"));
diff --git a/builtin/commit.c b/builtin/commit.c
@@ -1515,7 +1515,7 @@ static void print_summary(const char *prefix, const unsigned char *sha1,
 	rev.diffopt.break_opt = 0;
 	diff_setup_done(&rev.diffopt);
 
-	head = resolve_ref_unsafe("HEAD", junk_sha1, 0, NULL);
+	head = resolve_ref_unsafe("HEAD", 0, junk_sha1, NULL);
 	if (!strcmp(head, "HEAD"))
 		head = _("detached HEAD");
 	else
diff --git a/builtin/fmt-merge-msg.c b/builtin/fmt-merge-msg.c
@@ -602,7 +602,7 @@ int fmt_merge_msg(struct strbuf *in, struct strbuf *out,
 
 	/* get current branch */
 	current_branch = current_branch_to_free =
-		resolve_refdup("HEAD", head_sha1, 1, NULL);
+		resolve_refdup("HEAD", RESOLVE_REF_READING, head_sha1, NULL);
 	if (!current_branch)
 		die("No current branch");
 	if (starts_with(current_branch, "refs/heads/"))
diff --git a/builtin/for-each-ref.c b/builtin/for-each-ref.c
@@ -635,7 +635,8 @@ static void populate_value(struct refinfo *ref)
 
 	if (need_symref && (ref->flag & REF_ISSYMREF) && !ref->symref) {
 		unsigned char unused1[20];
-		ref->symref = resolve_refdup(ref->refname, unused1, 1, NULL);
+		ref->symref = resolve_refdup(ref->refname, RESOLVE_REF_READING,
+					     unused1, NULL);
 		if (!ref->symref)
 			ref->symref = "";
 	}
@@ -693,7 +694,8 @@ static void populate_value(struct refinfo *ref)
 			const char *head;
 			unsigned char sha1[20];
 
-			head = resolve_ref_unsafe("HEAD", sha1, 1, NULL);
+			head = resolve_ref_unsafe("HEAD", RESOLVE_REF_READING,
+						  sha1, NULL);
 			if (!strcmp(ref->refname, head))
 				v->s = "*";
 			else
diff --git a/builtin/fsck.c b/builtin/fsck.c
@@ -556,7 +556,7 @@ static int fsck_head_link(void)
 	if (verbose)
 		fprintf(stderr, "Checking HEAD link\n");
 
-	head_points_at = resolve_ref_unsafe("HEAD", head_sha1, 0, &flag);
+	head_points_at = resolve_ref_unsafe("HEAD", 0, head_sha1, &flag);
 	if (!head_points_at)
 		return error("Invalid HEAD");
 	if (!strcmp(head_points_at, "HEAD"))
diff --git a/builtin/log.c b/builtin/log.c
@@ -1400,7 +1400,8 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 		if (check_head) {
 			unsigned char sha1[20];
 			const char *ref, *v;
-			ref = resolve_ref_unsafe("HEAD", sha1, 1, NULL);
+			ref = resolve_ref_unsafe("HEAD", RESOLVE_REF_READING,
+						 sha1, NULL);
 			if (ref && skip_prefix(ref, "refs/heads/", &v))
 				branch_name = xstrdup(v);
 			else
diff --git a/builtin/merge.c b/builtin/merge.c
@@ -1101,7 +1101,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 	 * Check if we are _not_ on a detached HEAD, i.e. if there is a
 	 * current branch.
 	 */
-	branch = branch_to_free = resolve_refdup("HEAD", head_sha1, 0, &flag);
+	branch = branch_to_free = resolve_refdup("HEAD", 0, head_sha1, &flag);
 	if (branch && starts_with(branch, "refs/heads/"))
 		branch += 11;
 	if (!branch || is_null_sha1(head_sha1))
diff --git a/builtin/notes.c b/builtin/notes.c
@@ -702,7 +702,7 @@ static int merge_commit(struct notes_merge_options *o)
 	init_notes(t, "NOTES_MERGE_PARTIAL", combine_notes_overwrite, 0);
 
 	o->local_ref = local_ref_to_free =
-		resolve_refdup("NOTES_MERGE_REF", sha1, 0, NULL);
+		resolve_refdup("NOTES_MERGE_REF", 0, sha1, NULL);
 	if (!o->local_ref)
 		die("Failed to resolve NOTES_MERGE_REF");
 
diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
@@ -909,7 +909,7 @@ static void check_aliased_update(struct command *cmd, struct string_list *list)
 	int flag;
 
 	strbuf_addf(&buf, "%s%s", get_git_namespace(), cmd->ref_name);
-	dst_name = resolve_ref_unsafe(buf.buf, sha1, 0, &flag);
+	dst_name = resolve_ref_unsafe(buf.buf, 0, sha1, &flag);
 	strbuf_release(&buf);
 
 	if (!(flag & REF_ISSYMREF))
@@ -1070,7 +1070,7 @@ static void execute_commands(struct command *commands,
 	check_aliased_updates(commands);
 
 	free(head_name_to_free);
-	head_name = head_name_to_free = resolve_refdup("HEAD", sha1, 0, NULL);
+	head_name = head_name_to_free = resolve_refdup("HEAD", 0, sha1, NULL);
 
 	checked_connectivity = 1;
 	for (cmd = commands; cmd; cmd = cmd->next) {
diff --git a/builtin/remote.c b/builtin/remote.c
@@ -567,7 +567,8 @@ static int read_remote_branches(const char *refname,
 	strbuf_addf(&buf, "refs/remotes/%s/", rename->old);
 	if (starts_with(refname, buf.buf)) {
 		item = string_list_append(rename->remote_branches, xstrdup(refname));
-		symref = resolve_ref_unsafe(refname, orig_sha1, 1, &flag);
+		symref = resolve_ref_unsafe(refname, RESOLVE_REF_READING,
+					    orig_sha1, &flag);
 		if (flag & REF_ISSYMREF)
 			item->util = xstrdup(symref);
 		else
@@ -703,7 +704,7 @@ static int mv(int argc, const char **argv)
 		int flag = 0;
 		unsigned char sha1[20];
 
-		read_ref_full(item->string, sha1, 1, &flag);
+		read_ref_full(item->string, RESOLVE_REF_READING, sha1, &flag);
 		if (!(flag & REF_ISSYMREF))
 			continue;
 		if (delete_ref(item->string, NULL, REF_NODEREF))
diff --git a/builtin/show-branch.c b/builtin/show-branch.c
@@ -728,7 +728,9 @@ int cmd_show_branch(int ac, const char **av, const char *prefix)
 		if (ac == 0) {
 			static const char *fake_av[2];
 
-			fake_av[0] = resolve_refdup("HEAD", sha1, 1, NULL);
+			fake_av[0] = resolve_refdup("HEAD",
+						    RESOLVE_REF_READING,
+						    sha1, NULL);
 			fake_av[1] = NULL;
 			av = fake_av;
 			ac = 1;
@@ -789,7 +791,8 @@ int cmd_show_branch(int ac, const char **av, const char *prefix)
 		}
 	}
 
-	head_p = resolve_ref_unsafe("HEAD", head_sha1, 1, NULL);
+	head_p = resolve_ref_unsafe("HEAD", RESOLVE_REF_READING,
+				    head_sha1, NULL);
 	if (head_p) {
 		head_len = strlen(head_p);
 		memcpy(head, head_p, head_len + 1);
diff --git a/builtin/symbolic-ref.c b/builtin/symbolic-ref.c
@@ -13,7 +13,7 @@ static int check_symref(const char *HEAD, int quiet, int shorten, int print)
 {
 	unsigned char sha1[20];
 	int flag;
-	const char *refname = resolve_ref_unsafe(HEAD, sha1, 0, &flag);
+	const char *refname = resolve_ref_unsafe(HEAD, 0, sha1, &flag);
 
 	if (!refname)
 		die("No such ref: %s", HEAD);
diff --git a/bundle.c b/bundle.c
@@ -310,7 +310,7 @@ int create_bundle(struct bundle_header *header, const char *path,
 			continue;
 		if (dwim_ref(e->name, strlen(e->name), sha1, &ref) != 1)
 			continue;
-		if (read_ref_full(e->name, sha1, 1, &flag))
+		if (read_ref_full(e->name, RESOLVE_REF_READING, sha1, &flag))
 			flag = 0;
 		display_ref = (flag & REF_ISSYMREF) ? e->name : ref;
 
diff --git a/cache.h b/cache.h
@@ -950,8 +950,8 @@ extern int for_each_abbrev(const char *prefix, each_abbrev_fn, void *);
 extern int get_sha1_hex(const char *hex, unsigned char *sha1);
 
 extern char *sha1_to_hex(const unsigned char *sha1);	/* static buffer result! */
-extern int read_ref_full(const char *refname, unsigned char *sha1,
-			 int reading, int *flags);
+extern int read_ref_full(const char *refname, int resolve_flags,
+			 unsigned char *sha1, int *flags);
 extern int read_ref(const char *refname, unsigned char *sha1);
 
 /*
@@ -963,29 +963,30 @@ extern int read_ref(const char *refname, unsigned char *sha1);
  * or the input ref.
  *
  * If the reference cannot be resolved to an object, the behavior
- * depends on the "reading" argument:
+ * depends on the RESOLVE_REF_READING flag:
  *
- * - If reading is set, return NULL.
+ * - If RESOLVE_REF_READING is set, return NULL.
  *
- * - If reading is not set, clear sha1 and return the name of the last
- *   reference name in the chain, which will either be a non-symbolic
+ * - If RESOLVE_REF_READING is not set, clear sha1 and return the name of
+ *   the last reference name in the chain, which will either be a non-symbolic
  *   reference or an undefined reference.  If this is a prelude to
  *   "writing" to the ref, the return value is the name of the ref
  *   that will actually be created or changed.
  *
- * If flag is non-NULL, set the value that it points to the
+ * If flags is non-NULL, set the value that it points to the
  * combination of REF_ISPACKED (if the reference was found among the
- * packed references) and REF_ISSYMREF (if the initial reference was a
- * symbolic reference).
+ * packed references), REF_ISSYMREF (if the initial reference was a
+ * symbolic reference) and REF_ISBROKEN (if the ref is malformed).
  *
  * If ref is not a properly-formatted, normalized reference, return
  * NULL.  If more than MAXDEPTH recursive symbolic lookups are needed,
  * give up and return NULL.
  *
  * errno is set to something meaningful on error.
  */
-extern const char *resolve_ref_unsafe(const char *ref, unsigned char *sha1, int reading, int *flag);
-extern char *resolve_refdup(const char *ref, unsigned char *sha1, int reading, int *flag);
+#define RESOLVE_REF_READING 0x01
+extern const char *resolve_ref_unsafe(const char *ref, int resolve_flags, unsigned char *sha1, int *flags);
+extern char *resolve_refdup(const char *ref, int resolve_flags, unsigned char *sha1, int *flags);
 
 extern int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref);
 extern int dwim_log(const char *str, int len, unsigned char *sha1, char **ref);
diff --git a/http-backend.c b/http-backend.c
@@ -412,7 +412,9 @@ static int show_head_ref(const char *refname, const unsigned char *sha1,
 
 	if (flag & REF_ISSYMREF) {
 		unsigned char unused[20];
-		const char *target = resolve_ref_unsafe(refname, unused, 1, NULL);
+		const char *target = resolve_ref_unsafe(refname,
+							RESOLVE_REF_READING,
+							unused, NULL);
 		const char *target_nons = strip_namespace(target);
 
 		strbuf_addf(buf, "ref: %s\n", target_nons);
diff --git a/notes-merge.c b/notes-merge.c
@@ -549,7 +549,7 @@ int notes_merge(struct notes_merge_options *o,
 	       o->local_ref, o->remote_ref);
 
 	/* Dereference o->local_ref into local_sha1 */
-	if (read_ref_full(o->local_ref, local_sha1, 0, NULL))
+	if (read_ref_full(o->local_ref, 0, local_sha1, NULL))
 		die("Failed to resolve local notes ref '%s'", o->local_ref);
 	else if (!check_refname_format(o->local_ref, 0) &&
 		is_null_sha1(local_sha1))
diff --git a/reflog-walk.c b/reflog-walk.c
@@ -48,7 +48,8 @@ static struct complete_reflogs *read_complete_reflog(const char *ref)
 		unsigned char sha1[20];
 		const char *name;
 		void *name_to_free;
-		name = name_to_free = resolve_refdup(ref, sha1, 1, NULL);
+		name = name_to_free = resolve_refdup(ref, RESOLVE_REF_READING,
+						     sha1, NULL);
 		if (name) {
 			for_each_reflog_ent(name, read_one_reflog, reflogs);
 			free(name_to_free);
@@ -174,7 +175,7 @@ int add_reflog_for_walk(struct reflog_walk_info *info,
 		if (*branch == '\0') {
 			unsigned char sha1[20];
 			free(branch);
-			branch = resolve_refdup("HEAD", sha1, 0, NULL);
+			branch = resolve_refdup("HEAD", 0, sha1, NULL);
 			if (!branch)
 				die ("No current branch");
 
diff --git a/refs.c b/refs.c
diff --git a/remote.c b/remote.c
diff --git a/sequencer.c b/sequencer.c
diff --git a/transport-helper.c b/transport-helper.c
diff --git a/transport.c b/transport.c
diff --git a/upload-pack.c b/upload-pack.c
diff --git a/wt-status.c b/wt-status.c

Original file line number	Diff line number	Diff line change
`@@ -170,7 +170,7 @@ int validate_new_branchname(const char name, struct strbuf ref,`
`170`	`170`	`const char *head;`
`171`	`171`	`unsigned char sha1[20];`
`172`	`172`
`173`		`- head = resolve_ref_unsafe("HEAD", sha1, 0, NULL);`
	`173`	`+ head = resolve_ref_unsafe("HEAD", 0, sha1, NULL);`
`174`	`174`	`if (!is_bare_repository() && head && !strcmp(head, ref->buf))`
`175`	`175`	`die(_("Cannot force update the current branch."));`
`176`	`176`	`}`