builtin/refs.h: get worktrees without reading head info

In "packed-backend.c", there are some functions such as "create_snapshot"
and "next_record" which would check the correctness of the content of
the "packed-ref" file. When anything is bad, the program will die.

It may seem that we have nothing relevant to above feature, because we
are going to read and parse the raw "packed-ref" file without creating
the snapshot and using the ref iterator to check the consistency.

However, when using "get_worktrees" in "builtin/refs", we will parse the
head information. If the referent of the "HEAD" is inside the
"packed-ref", we will call "create_snapshot" and "next_record" functions
to parse the "packed-ref" to get the head information. And if there are
something wrong, the program will die.

Although this behavior has no harm for the program, it will
short-circuit the program. When the users execute "git refs verify" or
"git fsck", we don't want to simply die the program but rather show the
warnings or errors as many as possible to info the users. So, we should
avoiding reading the head info.

Fortunately, in 465a22b (worktree: skip reading HEAD when repairing
worktrees, 2023-12-29), we have introduced a function
"get_worktrees_internal" which allows us to get worktrees without
reading head info.

Create a new exposed function "get_worktrees_without_reading_head", then
replace the "get_worktrees" in "builtin/refs" with the new created
function.

Mentored-by: Patrick Steinhardt <[email protected]>
Mentored-by: Karthik Nayak <[email protected]>
Signed-off-by: shejialuo <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: shejialuo

builtin/refs.c

@@ -88,7 +88,7 @@ static int cmd_refs_verify(int argc, const char **argv, const char *prefix,
 	git_config(git_fsck_config, &fsck_refs_options);
 	prepare_repo_settings(the_repository);
 
-	worktrees = get_worktrees();
+	worktrees = get_worktrees_without_reading_head();
 	for (size_t i = 0; worktrees[i]; i++)
 		ret |= refs_fsck(get_worktree_ref_store(worktrees[i]),
 				 &fsck_refs_options, worktrees[i]);

worktree.c

@@ -175,6 +175,11 @@ struct worktree **get_worktrees(void)
 	return get_worktrees_internal(0);
 }
 
+struct worktree **get_worktrees_without_reading_head(void)
+{
+	return get_worktrees_internal(1);
+}
+
 const char *get_worktree_git_dir(const struct worktree *wt)
 {
 	if (!wt)

worktree.h

@@ -30,6 +30,12 @@ struct worktree {
  */
 struct worktree **get_worktrees(void);
 
+/*
+ * Like `get_worktrees`, but does not read HEAD. This is useful when checking
+ * the consistency, as reading HEAD may not be necessary.
+ */
+struct worktree **get_worktrees_without_reading_head(void);
+
 /*
  * Returns 1 if linked worktrees exist, 0 otherwise.
  */