This patch annotates merge commits shown in 'tog diff' with information
about the multiple parent commits. The 'got log' command already displays
parents of merge commits in the same way.

ok?

diff 0e5df9843b907e2f3bb8bae341f4ac0d5762346a /home/stsp/src/got
blob - cbf77a99b234b7a155644a3abe25adda577f1a8d
file + tog/tog.c
--- tog/tog.c
+++ tog/tog.c
@@ -3227,6 +3227,29 @@ write_commit_info(off_t **line_offsets, size_t *nlines
 		if (err)
 			goto done;
 	}
+	if (got_object_commit_get_nparents(commit) > 1) {
+		const struct got_object_id_queue *parent_ids;
+		struct got_object_qid *qid;
+		int pn = 1;
+		parent_ids = got_object_commit_get_parent_ids(commit);
+		STAILQ_FOREACH(qid, parent_ids, entry) {
+			err = got_object_id_str(&id_str, qid->id);
+			if (err)
+				goto done;
+			n = fprintf(outfile, "parent %d: %s\n", pn++, id_str);
+			if (n < 0) {
+				err = got_error_from_errno("fprintf");
+				goto done;
+			}
+			outoff += n;
+			err = add_line_offset(line_offsets, nlines, outoff);
+			if (err)
+				goto done;
+			free(id_str);
+			id_str = NULL;
+		}
+	}
+
 	err = got_object_commit_get_logmsg(&logmsg, commit);
 	if (err)
 		goto done;
@@ -3528,8 +3551,8 @@ open_diff_view(struct tog_view *view, struct got_objec
 		}
 
 		err = add_color(&s->colors,
-		    "^(commit [0-9a-f]|(blob|file) [-+] |[MDmA]  [^ ])",
-		    TOG_COLOR_DIFF_META,
+		    "^(commit [0-9a-f]|parent [0-9]|(blob|file) [-+] |"
+		    "[MDmA]  [^ ])", TOG_COLOR_DIFF_META,
 		    get_color_value("TOG_COLOR_DIFF_META"));
 		if (err) {
 			free_colors(&s->colors);