From: Omar Polo <op@omarpolo.com>
Subject: Re: tog log reference labels
To: Stefan Sperling <stsp@stsp.name>
Cc: gameoftrees@openbsd.org
Date: Tue, 16 May 2023 11:30:45 +0200

On 2023/05/15 20:25:21 +0200, Stefan Sperling <stsp@stsp.name> wrote:
> On Mon, May 15, 2023 at 06:38:25PM +0200, Omar Polo wrote:
> > On 2023/05/15 18:11:35 +0200, Stefan Sperling <stsp@stsp.name> wrote:
> > > Show reference labels next to commit messages in the tog log view.
> > > Requested by mpi@
> > > 
> > > ok?
> > 
> > that's nice, i like it too.  ok op@
> > 
> > suggestion below
> 
> Thanks! I have committed it as-is.
> 
> Feel free to commit your suggestion on top. I am OK with that.

I've found that my suggestion could result in a segfault.  This
because the reflist may include uninteresting refs in the refs/got/
namespace that gets filtered out by build_refs_str.

If a commit happens to have only uninteresting refs pointing to it
(e.g. when you have worktrees not up-to-date), build_refs_str returns
NULL, whihc is not handled here.

I'm attaching a diff with a way to handle it.  Another way would be to
relax build_refs_str to allow a NULL refs being passed.

diff /home/op/w/gotacl
commit - 276bccc4651afa03134d0faa1cf1c703b5f819bd
path + /home/op/w/gotacl
blob - 25bddbc9c0a8c95dc7b5008c82de519be7d36960
file + tog/tog.c
--- tog/tog.c
+++ tog/tog.c
@@ -2401,6 +2401,7 @@ draw_commit(struct tog_view *view, struct got_commit_o
 	struct tog_log_view_state *s = &view->state.log;
 	const struct got_error *err = NULL;
 	char datebuf[12]; /* YYYY-MM-DD + SPACE + NUL */
+	char *refs_str = NULL;
 	char *logmsg0 = NULL, *logmsg = NULL;
 	char *author = NULL;
 	wchar_t *wlogmsg = NULL, *wauthor = NULL;
@@ -2495,13 +2496,13 @@ draw_commit(struct tog_view *view, struct got_commit_o
 
 	/* Prepend reference labels to log message if possible .*/
 	refs = got_reflist_object_id_map_lookup(tog_refs_idmap, id);
-	if (refs) {
-		char *refs_str, *newlogmsg;
-		wchar_t *ws;
-
+	if (refs)
 		err = build_refs_str(&refs_str, refs, id, s->repo);
-		if (err)
-			goto done;
+	if (err)
+		goto done;
+	if (refs_str) {
+		char *newlogmsg;
+		wchar_t *ws;
 	
 		/*
 		 * The length of this wide-char sub-string will be
@@ -2516,10 +2517,8 @@ draw_commit(struct tog_view *view, struct got_commit_o
 
 		if (asprintf(&newlogmsg, "[%s] %s", refs_str, logmsg) == -1) {
 			err = got_error_from_errno("asprintf");
-			free(refs_str);
 			goto done;
 		}
-		free(refs_str);
 
 		free(logmsg0);
 		logmsg0 = newlogmsg;
@@ -2554,6 +2553,7 @@ done:
 done:
 	free(logmsg0);
 	free(wlogmsg);
+	free(refs_str);
 	free(author);
 	free(wauthor);
 	free(line);