mailmap: plug memory leak in read_mailmap_blob()

When a named object to read mailmap from is not a blob, the code
correctly errors out, but it forgot to free the object data before
doing so.

Signed-off-by: Junio C Hamano <[email protected]>

Author: gitster

mailmap.c

@@ -201,8 +201,10 @@ static int read_mailmap_blob(struct string_list *map, const char *name)
 	buf = repo_read_object_file(the_repository, &oid, &type, &size);
 	if (!buf)
 		return error("unable to read mailmap object at %s", name);
-	if (type != OBJ_BLOB)
+	if (type != OBJ_BLOB) {
+		free(buf);
 		return error("mailmap is not a blob: %s", name);
+	}
 
 	read_mailmap_string(map, buf);
 

t/t4203-mailmap.sh

@@ -5,6 +5,7 @@ test_description='.mailmap configurations'
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_expect_success 'setup commits and contacts file' '