refs: move resolve_ref_unsafe into common code

Now that resolve_ref_unsafe's only interaction with the backend is
through read_raw_ref, we can move it into the common code. Later,
we'll replace read_raw_ref with a backend function.

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

3 files changed, 83 insertions, 79 deletions

diff --git a/refs.c b/refs.c
index f0feff72da..87dc82f1d8 100644
--- a/refs.c
+++ b/refs.c
@@ -1155,3 +1155,77 @@ int for_each_rawref(each_ref_fn fn, void *cb_data)
 	return do_for_each_ref(NULL, "", fn, 0,
 			       DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
 }
+
+/* This function needs to return a meaningful errno on failure */
+const char *resolve_ref_unsafe(const char *refname, int resolve_flags,
+			       unsigned char *sha1, int *flags)
+{
+	static struct strbuf sb_refname = STRBUF_INIT;
+	int unused_flags;
+	int symref_count;
+
+	if (!flags)
+		flags = &unused_flags;
+
+	*flags = 0;
+
+	if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
+		if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
+		    !refname_is_safe(refname)) {
+			errno = EINVAL;
+			return NULL;
+		}
+
+		/*
+		 * dwim_ref() uses REF_ISBROKEN to distinguish between
+		 * missing refs and refs that were present but invalid,
+		 * to complain about the latter to stderr.
+		 *
+		 * We don't know whether the ref exists, so don't set
+		 * REF_ISBROKEN yet.
+		 */
+		*flags |= REF_BAD_NAME;
+	}
+
+	for (symref_count = 0; symref_count < SYMREF_MAXDEPTH; symref_count++) {
+		unsigned int read_flags = 0;
+
+		if (read_raw_ref(refname, sha1, &sb_refname, &read_flags)) {
+			*flags |= read_flags;
+			if (errno != ENOENT || (resolve_flags & RESOLVE_REF_READING))
+				return NULL;
+			hashclr(sha1);
+			if (*flags & REF_BAD_NAME)
+				*flags |= REF_ISBROKEN;
+			return refname;
+		}
+
+		*flags |= read_flags;
+
+		if (!(read_flags & REF_ISSYMREF)) {
+			if (*flags & REF_BAD_NAME) {
+				hashclr(sha1);
+				*flags |= REF_ISBROKEN;
+			}
+			return refname;
+		}
+
+		refname = sb_refname.buf;
+		if (resolve_flags & RESOLVE_REF_NO_RECURSE) {
+			hashclr(sha1);
+			return refname;
+		}
+		if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
+			if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
+			    !refname_is_safe(refname)) {
+				errno = EINVAL;
+				return NULL;
+			}
+
+			*flags |= REF_ISBROKEN | REF_BAD_NAME;
+		}
+	}
+
+	errno = ELOOP;
+	return NULL;
+}
diff --git a/refs/files-backend.c b/refs/files-backend.c
index a15986ccc2..71848ab9d6 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -1269,8 +1269,6 @@ static struct ref_dir *get_loose_refs(struct ref_cache *refs)
 	return get_ref_dir(refs->loose);
 }
 
-/* We allow "recursive" symbolic refs. Only within reason, though */
-#define MAXDEPTH 5
 #define MAXREFLEN (1024)
 
 /*
@@ -1300,7 +1298,7 @@ static int resolve_gitlink_ref_recursive(struct ref_cache *refs,
 	char buffer[128], *p;
 	char *path;
 
-	if (recursion > MAXDEPTH || strlen(refname) > MAXREFLEN)
+	if (recursion > SYMREF_MAXDEPTH || strlen(refname) > MAXREFLEN)
 		return -1;
 	path = *refs->name
 		? git_pathdup_submodule(refs->name, "%s", refname)
@@ -1420,8 +1418,8 @@ static int resolve_missing_loose_ref(const char *refname,
  * - in all other cases, symref will be untouched, and therefore
  *   refname will still be valid and unchanged.
  */
-static int read_raw_ref(const char *refname, unsigned char *sha1,
-			struct strbuf *symref, unsigned int *flags)
+int read_raw_ref(const char *refname, unsigned char *sha1,
+		 struct strbuf *symref, unsigned int *flags)
 {
 	struct strbuf sb_contents = STRBUF_INIT;
 	struct strbuf sb_path = STRBUF_INIT;
@@ -1538,80 +1536,6 @@ out:
 	return ret;
 }
 
-/* This function needs to return a meaningful errno on failure */
-const char *resolve_ref_unsafe(const char *refname, int resolve_flags,
-			       unsigned char *sha1, int *flags)
-{
-	static struct strbuf sb_refname = STRBUF_INIT;
-	int unused_flags;
-	int symref_count;
-
-	if (!flags)
-		flags = &unused_flags;
-
-	*flags = 0;
-
-	if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
-		if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
-		    !refname_is_safe(refname)) {
-			errno = EINVAL;
-			return NULL;
-		}
-
-		/*
-		 * dwim_ref() uses REF_ISBROKEN to distinguish between
-		 * missing refs and refs that were present but invalid,
-		 * to complain about the latter to stderr.
-		 *
-		 * We don't know whether the ref exists, so don't set
-		 * REF_ISBROKEN yet.
-		 */
-		*flags |= REF_BAD_NAME;
-	}
-
-	for (symref_count = 0; symref_count < MAXDEPTH; symref_count++) {
-		unsigned int read_flags = 0;
-
-		if (read_raw_ref(refname, sha1, &sb_refname, &read_flags)) {
-			*flags |= read_flags;
-			if (errno != ENOENT || (resolve_flags & RESOLVE_REF_READING))
-				return NULL;
-			hashclr(sha1);
-			if (*flags & REF_BAD_NAME)
-				*flags |= REF_ISBROKEN;
-			return refname;
-		}
-
-		*flags |= read_flags;
-
-		if (!(read_flags & REF_ISSYMREF)) {
-			if (*flags & REF_BAD_NAME) {
-				hashclr(sha1);
-				*flags |= REF_ISBROKEN;
-			}
-			return refname;
-		}
-
-		refname = sb_refname.buf;
-		if (resolve_flags & RESOLVE_REF_NO_RECURSE) {
-			hashclr(sha1);
-			return refname;
-		}
-		if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
-			if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
-			    !refname_is_safe(refname)) {
-				errno = EINVAL;
-				return NULL;
-			}
-
-			*flags |= REF_ISBROKEN | REF_BAD_NAME;
-		}
-	}
-
-	errno = ELOOP;
-	return NULL;
-}
-
 /*
  * Peel the entry (if possible) and return its new peel_status.  If
  * repeel is true, re-peel the entry even if there is an old peeled
diff --git a/refs/refs-internal.h b/refs/refs-internal.h
index 92aae80c21..3a4f634cb4 100644
--- a/refs/refs-internal.h
+++ b/refs/refs-internal.h
@@ -197,6 +197,8 @@ const char *find_descendant_ref(const char *dirname,
 
 int rename_ref_available(const char *oldname, const char *newname);
 
+/* We allow "recursive" symbolic refs. Only within reason, though */
+#define SYMREF_MAXDEPTH 5
 
 /* Include broken references in a do_for_each_ref*() iteration: */
 #define DO_FOR_EACH_INCLUDE_BROKEN 0x01
@@ -206,4 +208,8 @@ int rename_ref_available(const char *oldname, const char *newname);
  */
 int do_for_each_ref(const char *submodule, const char *base,
 		    each_ref_fn fn, int trim, int flags, void *cb_data);
+
+int read_raw_ref(const char *refname, unsigned char *sha1,
+		 struct strbuf *symref, unsigned int *flags);
+
 #endif /* REFS_REFS_INTERNAL_H */