From 424dcc7683a37d1f14aa0dd485300001cb854f6c Mon Sep 17 00:00:00 2001
From: Michael Haggerty <mhagger@alum.mit.edu>
Date: Sun, 4 Sep 2016 18:08:22 +0200
Subject: resolve_gitlink_ref(): implement using resolve_ref_recursively()

resolve_ref_recursively() can handle references in arbitrary files
reference stores, so use it to resolve "gitlink" (i.e., submodule)
references. Aside from removing redundant code, this allows submodule
lookups to benefit from the much more robust code that we use for
reading non-submodule references. And, since the code is now agnostic
about reference backends, it will work for any future references
backend (so move its definition to refs.c).

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/refs.c b/refs.c
index 464fe71..7b86b4e 100644
--- a/refs.c
+++ b/refs.c
@@ -1299,6 +1299,30 @@ const char *resolve_ref_unsafe(const char *refname, int resolve_flags,
 				       resolve_flags, sha1, flags);
 }
 
+int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1)
+{
+	int len = strlen(path);
+	struct strbuf submodule = STRBUF_INIT;
+	struct ref_store *refs;
+	int flags;
+
+	while (len && path[len-1] == '/')
+		len--;
+	if (!len)
+		return -1;
+
+	strbuf_add(&submodule, path, len);
+	refs = get_ref_store(submodule.buf);
+	strbuf_release(&submodule);
+	if (!refs)
+		return -1;
+
+	if (!resolve_ref_recursively(refs, refname, 0, sha1, &flags) ||
+	    is_null_sha1(sha1))
+		return -1;
+	return 0;
+}
+
 /* A pointer to the ref_store for the main repository: */
 static struct ref_store *main_ref_store;
 
diff --git a/refs/files-backend.c b/refs/files-backend.c
index a743da4..979cee8 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -1494,73 +1494,6 @@ static void unlock_ref(struct ref_lock *lock)
 	free(lock);
 }
 
-#define MAXREFLEN (1024)
-
-static int resolve_gitlink_ref_recursive(struct files_ref_store *refs,
-					 const char *refname, unsigned char *sha1,
-					 int recursion)
-{
-	int fd, len;
-	char buffer[128], *p;
-	char *path;
-
-	if (recursion > SYMREF_MAXDEPTH || strlen(refname) > MAXREFLEN)
-		return -1;
-	path = *refs->base.submodule
-		? git_pathdup_submodule(refs->base.submodule, "%s", refname)
-		: git_pathdup("%s", refname);
-	fd = open(path, O_RDONLY);
-	free(path);
-	if (fd < 0) {
-		unsigned int flags;
-
-		return resolve_packed_ref(refs, refname, sha1, &flags);
-	}
-
-	len = read(fd, buffer, sizeof(buffer)-1);
-	close(fd);
-	if (len < 0)
-		return -1;
-	while (len && isspace(buffer[len-1]))
-		len--;
-	buffer[len] = 0;
-
-	/* Was it a detached head or an old-fashioned symlink? */
-	if (!get_sha1_hex(buffer, sha1))
-		return 0;
-
-	/* Symref? */
-	if (strncmp(buffer, "ref:", 4))
-		return -1;
-	p = buffer + 4;
-	while (isspace(*p))
-		p++;
-
-	return resolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);
-}
-
-int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1)
-{
-	int len = strlen(path);
-	struct strbuf submodule = STRBUF_INIT;
-	struct files_ref_store *refs;
-
-	while (len && path[len-1] == '/')
-		len--;
-	if (!len)
-		return -1;
-
-	strbuf_add(&submodule, path, len);
-	refs = get_files_ref_store(submodule.buf, "resolve_gitlink_ref");
-	if (!refs) {
-		strbuf_release(&submodule);
-		return -1;
-	}
-	strbuf_release(&submodule);
-
-	return resolve_gitlink_ref_recursive(refs, refname, sha1, 0);
-}
-
 /*
  * Lock refname, without following symrefs, and set *lock_p to point
  * at a newly-allocated lock object. Fill in lock->old_oid, referent,
-- 
cgit v0.10.2-6-g49f6