Merge branch 'sj/ref-contents-check' into next

"git fsck" learned to issue warnings on "curiously formatted" ref
contents that have always been taken valid but something Git
wouldn't have written itself (e.g., missing terminating end-of-line
after the full object name).

* sj/ref-contents-check:
  ref: add symlink ref content check for files backend
  ref: check whether the target of the symref is a ref
  ref: add basic symref content check for files backend
  ref: add more strict checks for regular refs
  ref: port git-fsck(1) regular refs check for files backend
  ref: support multiple worktrees check for refs
  ref: initialize ref name outside of check functions
  ref: check the full refname instead of basename
  ref: initialize "fsck_ref_report" with zero

Documentation/fsck-msgids.txt

@@ -19,12 +19,18 @@
 `badParentSha1`::
 	(ERROR) A commit object has a bad parent sha1.
 
+`badRefContent`::
+	(ERROR) A ref has bad content.
+
 `badRefFiletype`::
 	(ERROR) A ref has a bad file type.
 
 `badRefName`::
 	(ERROR) A ref has an invalid format.
 
+`badReferentName`::
+	(ERROR) The referent name of a symref is invalid.
+
 `badTagName`::
 	(INFO) A tag has an invalid format.
 
@@ -170,6 +176,35 @@
 `nullSha1`::
 	(WARN) Tree contains entries pointing to a null sha1.
 
+`refMissingNewline`::
+	(INFO) A loose ref that does not end with newline(LF). As
+	valid implementations of Git never created such a loose ref
+	file, it may become an error in the future. Report to the
+	[email protected] mailing list if you see this error, as
+	we need to know what tools created such a file.
+
+`symlinkRef`::
+	(INFO) A symbolic link is used as a symref. Report to the
+	[email protected] mailing list if you see this error, as we
+	are assessing the feasibility of dropping the support to drop
+	creating symbolic links as symrefs.
+
+`symrefTargetIsNotARef`::
+	(INFO) The target of a symbolic reference points neither to
+	a root reference nor to a reference starting with "refs/".
+	Although we allow create a symref pointing to the referent which
+	is outside the "ref" by using `git symbolic-ref`, we may tighten
+	the rule in the future. Report to the [email protected]
+	mailing list if you see this error, as we need to know what tools
+	created such a file.
+
+`trailingRefContent`::
+	(INFO) A loose ref has trailing content. As valid implementations
+	of Git never created such a loose ref file, it may become an
+	error in the future. Report to the [email protected] mailing
+	list if you see this error, as we need to know what tools
+	created such a file.
+
 `treeNotSorted`::
 	(ERROR) A tree is not properly sorted.
 

builtin/refs.c

@@ -5,6 +5,7 @@
 #include "parse-options.h"
 #include "refs.h"
 #include "strbuf.h"
+#include "worktree.h"
 
 #define REFS_MIGRATE_USAGE \
 	N_("git refs migrate --ref-format=<format> [--dry-run]")
@@ -66,6 +67,7 @@ static int cmd_refs_migrate(int argc, const char **argv, const char *prefix)
 static int cmd_refs_verify(int argc, const char **argv, const char *prefix)
 {
 	struct fsck_options fsck_refs_options = FSCK_REFS_OPTIONS_DEFAULT;
+	struct worktree **worktrees;
 	const char * const verify_usage[] = {
 		REFS_VERIFY_USAGE,
 		NULL,
@@ -75,7 +77,7 @@ static int cmd_refs_verify(int argc, const char **argv, const char *prefix)
 		OPT_BOOL(0, "strict", &fsck_refs_options.strict, N_("enable strict checking")),
 		OPT_END(),
 	};
-	int ret;
+	int ret = 0;
 
 	argc = parse_options(argc, argv, prefix, options, verify_usage, 0);
 	if (argc)
@@ -84,9 +86,13 @@ 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);
 
-	ret = refs_fsck(get_main_ref_store(the_repository), &fsck_refs_options);
+	worktrees = get_worktrees();
+	for (size_t i = 0; worktrees[i]; i++)
+		ret |= refs_fsck(get_worktree_ref_store(worktrees[i]),
+				 &fsck_refs_options, worktrees[i]);
 
 	fsck_options_clear(&fsck_refs_options);
+	free_worktrees(worktrees);
 	return ret;
 }
 

fsck.h

@@ -31,8 +31,10 @@ enum fsck_msg_type {
 	FUNC(BAD_NAME, ERROR) \
 	FUNC(BAD_OBJECT_SHA1, ERROR) \
 	FUNC(BAD_PARENT_SHA1, ERROR) \
+	FUNC(BAD_REF_CONTENT, ERROR) \
 	FUNC(BAD_REF_FILETYPE, ERROR) \
 	FUNC(BAD_REF_NAME, ERROR) \
+	FUNC(BAD_REFERENT_NAME, ERROR) \
 	FUNC(BAD_TIMEZONE, ERROR) \
 	FUNC(BAD_TREE, ERROR) \
 	FUNC(BAD_TREE_SHA1, ERROR) \
@@ -84,6 +86,10 @@ enum fsck_msg_type {
 	FUNC(MAILMAP_SYMLINK, INFO) \
 	FUNC(BAD_TAG_NAME, INFO) \
 	FUNC(MISSING_TAGGER_ENTRY, INFO) \
+	FUNC(SYMLINK_REF, INFO) \
+	FUNC(REF_MISSING_NEWLINE, INFO) \
+	FUNC(SYMREF_TARGET_IS_NOT_A_REF, INFO) \
+	FUNC(TRAILING_REF_CONTENT, INFO) \
 	/* ignored (elevated when requested) */ \
 	FUNC(EXTRA_HEADER_ENTRY, IGNORE)
 

refs.c

@@ -318,9 +318,10 @@ int check_refname_format(const char *refname, int flags)
 	return check_or_sanitize_refname(refname, flags, NULL);
 }
 
-int refs_fsck(struct ref_store *refs, struct fsck_options *o)
+int refs_fsck(struct ref_store *refs, struct fsck_options *o,
+	      struct worktree *wt)
 {
-	return refs->be->fsck(refs, o);
+	return refs->be->fsck(refs, o, wt);
 }
 
 void sanitize_refname_component(const char *refname, struct strbuf *out)
@@ -1791,7 +1792,7 @@ static int refs_read_special_head(struct ref_store *ref_store,
 	}
 
 	result = parse_loose_ref_contents(ref_store->repo->hash_algo, content.buf,
-					  oid, referent, type, failure_errno);
+					  oid, referent, type, NULL, failure_errno);
 
 done:
 	strbuf_release(&full_path);

refs.h

@@ -550,7 +550,8 @@ int check_refname_format(const char *refname, int flags);
  * reflogs are consistent, and non-zero otherwise. The errors will be
  * written to stderr.
  */
-int refs_fsck(struct ref_store *refs, struct fsck_options *o);
+int refs_fsck(struct ref_store *refs, struct fsck_options *o,
+	      struct worktree *wt);
 
 /*
  * Apply the rules from check_refname_format, but mutate the result until it

refs/debug.c

@@ -408,10 +408,11 @@ static int debug_reflog_expire(struct ref_store *ref_store, const char *refname,
 }
 
 static int debug_fsck(struct ref_store *ref_store,
-		      struct fsck_options *o)
+		      struct fsck_options *o,
+		      struct worktree *wt)
 {
 	struct debug_ref_store *drefs = (struct debug_ref_store *)ref_store;
-	int res = drefs->refs->be->fsck(drefs->refs, o);
+	int res = drefs->refs->be->fsck(drefs->refs, o, wt);
 	trace_printf_key(&trace_refs, "fsck: %d\n", res);
 	return res;
 }