refs.c: add resolve_ref_submodule()

This is basically the extended version of resolve_gitlink_ref() where we
have access to more info from the underlying resolve_ref_recursively() call.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

2 files changed, 17 insertions, 6 deletions

diff --git a/refs.c b/refs.c
index 9bd0bc177b..f6226070e1 100644
--- a/refs.c
+++ b/refs.c
@@ -1320,18 +1320,18 @@ const char *resolve_ref_unsafe(const char *refname, int resolve_flags,
 				       resolve_flags, sha1, flags);
 }
 
-int resolve_gitlink_ref(const char *submodule, const char *refname,
-			unsigned char *sha1)
+const char *resolve_ref_submodule(const char *submodule, const char *refname,
+				  int resolve_flags, unsigned char *sha1,
+				  int *flags)
 {
 	size_t len = strlen(submodule);
 	struct ref_store *refs;
-	int flags;
 
 	while (len && submodule[len - 1] == '/')
 		len--;
 
 	if (!len)
-		return -1;
+		return NULL;
 
 	if (submodule[len]) {
 		/* We need to strip off one or more trailing slashes */
@@ -1344,9 +1344,17 @@ int resolve_gitlink_ref(const char *submodule, const char *refname,
 	}
 
 	if (!refs)
-		return -1;
+		return NULL;
+
+	return resolve_ref_recursively(refs, refname, resolve_flags, sha1, flags);
+}
+
+int resolve_gitlink_ref(const char *submodule, const char *refname,
+			unsigned char *sha1)
+{
+	int flags;
 
-	if (!resolve_ref_recursively(refs, refname, 0, sha1, &flags) ||
+	if (!resolve_ref_submodule(submodule, refname, 0, sha1, &flags) ||
 	    is_null_sha1(sha1))
 		return -1;
 	return 0;
diff --git a/refs.h b/refs.h
index 6947843913..576e73305f 100644
--- a/refs.h
+++ b/refs.h
@@ -86,6 +86,9 @@ int peel_ref(const char *refname, unsigned char *sha1);
  */
 int resolve_gitlink_ref(const char *submodule, const char *refname,
 			unsigned char *sha1);
+const char *resolve_ref_submodule(const char *submodule, const char *refname,
+				  int resolve_flags, unsigned char *sha1,
+				  int *flags);
 
 /*
  * Return true iff abbrev_name is a possible abbreviation for