Compare repository idle times by sign

The idle-sort comparator returned a 64-bit time difference truncated
to int, which could flip sign and leave the ordering inconsistent.

1 file changed, 7 insertions, 1 deletion

diff --git a/source/ui-repolist.c b/source/ui-repolist.c
index fc198e5..9c4fd6f 100644
--- a/source/ui-repolist.c
+++ b/source/ui-repolist.c
@@ -242,7 +242,13 @@ static int sort_idle(const void *a, const void *b)
 	t1 = t2 = 0;
 	get_repo_modtime(r1, &t1);
 	get_repo_modtime(r2, &t2);
-	return t2 - t1;
+	/* Return the sign only; a truncated 64-bit time_t difference could
+	 * flip and make the comparator inconsistent. */
+	if (t2 > t1)
+		return 1;
+	if (t2 < t1)
+		return -1;
+	return 0;
 }
 
 static int sort_section(const void *a, const void *b)