refs: convert parameter of create_dir_entry() to length-limited string

Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/refs.c b/refs.c
index c028333..c5e167b 100644
--- a/refs.c
+++ b/refs.c
@@ -294,12 +294,13 @@
  * "refs/heads/") or "" for the top-level directory.
  */
 static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache,
-					  const char *dirname, int incomplete)
+					  const char *dirname, size_t len,
+					  int incomplete)
 {
 	struct ref_entry *direntry;
-	int len = strlen(dirname);
 	direntry = xcalloc(1, sizeof(struct ref_entry) + len + 1);
-	memcpy(direntry->name, dirname, len + 1);
+	memcpy(direntry->name, dirname, len);
+	direntry->name[len] = '\0';
 	direntry->u.subdir.ref_cache = ref_cache;
 	direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE : 0);
 	return direntry;
@@ -364,7 +365,7 @@
 		 * therefore, create an empty record for it but mark
 		 * the record complete.
 		 */
-		entry = create_dir_entry(dir->ref_cache, subdirname, 0);
+		entry = create_dir_entry(dir->ref_cache, subdirname, len, 0);
 		add_entry_to_dir(dir, entry);
 	}
 	return get_ref_dir(entry);
@@ -823,7 +824,7 @@
 		const char *packed_refs_file;
 		FILE *f;
 
-		refs->packed = create_dir_entry(refs, "", 0);
+		refs->packed = create_dir_entry(refs, "", 0, 0);
 		if (*refs->name)
 			packed_refs_file = git_path_submodule(refs->name, "packed-refs");
 		else
@@ -888,7 +889,8 @@
 		} else if (S_ISDIR(st.st_mode)) {
 			strbuf_addch(&refname, '/');
 			add_entry_to_dir(dir,
-					 create_dir_entry(refs, refname.buf, 1));
+					 create_dir_entry(refs, refname.buf,
+							  refname.len, 1));
 		} else {
 			if (*refs->name) {
 				hashclr(sha1);
@@ -918,12 +920,12 @@
 		 * are about to read the only subdirectory that can
 		 * hold references:
 		 */
-		refs->loose = create_dir_entry(refs, "", 0);
+		refs->loose = create_dir_entry(refs, "", 0, 0);
 		/*
 		 * Create an incomplete entry for "refs/":
 		 */
 		add_entry_to_dir(get_ref_dir(refs->loose),
-				 create_dir_entry(refs, "refs/", 1));
+				 create_dir_entry(refs, "refs/", 5, 1));
 	}
 	return get_ref_dir(refs->loose);
 }