submodule.c: report the submodule that an error occurs in

diff --git a/builtin/am.c b/builtin/am.c
index a02d5186cb9fabe4472ab1022fe00ec89349f5af..acfe9d3c8cd6dbd8362c17d55dc036ce6682ce8a 100644 (file)
--- a/builtin/am.c
+++ b/builtin/am.c
@@ -708,6 +708,7 @@ static int split_mail_mbox(struct am_state *state, const char **paths,
 {
        struct child_process cp = CHILD_PROCESS_INIT;
        struct strbuf last = STRBUF_INIT;
+       int ret;
 
        cp.git_cmd = 1;
        argv_array_push(&cp.args, "mailsplit");
@@ -721,13 +722,16 @@ static int split_mail_mbox(struct am_state *state, const char **paths,
        argv_array_push(&cp.args, "--");
        argv_array_pushv(&cp.args, paths);
 
-       if (capture_command(&cp, &last, 8))
-               return -1;
+       ret = capture_command(&cp, &last, 8);
+       if (ret)
+               goto exit;
 
        state->cur = 1;
        state->last = strtol(last.buf, NULL, 10);
 
-       return 0;
+exit:
+       strbuf_release(&last);
+       return ret ? -1 : 0;
 }
 
 /**