Remove redundant checks for the empty overlay tree

* src/alloc.c (mark_buffer): Remove b->overlays check.
* src/buffer.c (copy_overlays): Also.
* src/buffer.c (swap_buffer_overlays, overlays_in): Also.
  (next_overlay_change, previous_overlay_change): Also.
  (overlay_touches_p, Foverlay_lists): Also.
  (evaporate_overlays): Also.
* src/xdisp.c (load_overlay_strings): Also.

1 files changed, 5 insertions, 9 deletions

diff --git a/src/alloc.c b/src/alloc.c
index 15a6fc43b72..9f72f914e00 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -6306,15 +6306,11 @@ mark_buffer (struct buffer *buffer)
      a special way just before the sweep phase, and after stripping
      some of its elements that are not needed any more.  */
 
-  if (buffer->overlays)
-    {
-      struct interval_node *node;
-      buffer_overlay_iter_start (buffer, PTRDIFF_MIN, PTRDIFF_MAX, ITREE_ASCENDING);
-
-      while ((node = buffer_overlay_iter_next (buffer)))
-        mark_overlay (XOVERLAY (node->data));
-      buffer_overlay_iter_finish (buffer);
-    }
+  struct interval_node *node;
+  buffer_overlay_iter_start (buffer, PTRDIFF_MIN, PTRDIFF_MAX, ITREE_ASCENDING);
+  while ((node = buffer_overlay_iter_next (buffer)))
+    mark_overlay (XOVERLAY (node->data));
+  buffer_overlay_iter_finish (buffer);
 
   /* If this is an indirect buffer, mark its base buffer.  */
   if (buffer->base_buffer && !VECTOR_MARKED_P (buffer->base_buffer))