libFLAC/format.c: Fix undefined behaviour
In the case where seek_table->num_points is zero, seek_table->points
will be NULL and passing that to qsort() invokes undefined behaviour.
Since seek_table->num_points is zero, the only sensible thing to do
is to short circuit return 0.
diff --git a/src/libFLAC/format.c b/src/libFLAC/format.c
index 0f601af..0b1d10b 100644
--- a/src/libFLAC/format.c
+++ b/src/libFLAC/format.c
@@ -275,6 +275,9 @@
FLAC__ASSERT(0 != seek_table);
+ if (seek_table->num_points == 0)
+ return 0;
+
/* sort the seekpoints */
qsort(seek_table->points, seek_table->num_points, sizeof(FLAC__StreamMetadata_SeekPoint), (int (*)(const void *, const void *))seekpoint_compare_);