Improve preserving X coordinate during scroll commands

* src/window.c (window_scroll_pixel_based): Don't unnecessarily
move the iterator.  (Bug#53220)

diff --git a/src/window.c b/src/window.c
index 7155f0e6bc363f859deb1dfae12cc8f0109bbb18..2a5e4042a48dfc3503461433ca4a3beb0acea8f8 100644 (file)
--- a/src/window.c
+++ b/src/window.c
@@ -5861,7 +5861,8 @@ window_scroll_pixel_based (Lisp_Object window, int n, bool whole, bool noerror)
 
       /* We moved the window start towards ZV, so PT may be now
         in the scroll margin at the top.  */
-      move_it_to (&it, PT, -1, -1, -1, MOVE_TO_POS);
+      if (IT_CHARPOS (it) < PT)
+       move_it_to (&it, PT, -1, -1, -1, MOVE_TO_POS);
       if (IT_CHARPOS (it) == PT
          && it.current_y >= this_scroll_margin
          && it.current_y <= last_y - WINDOW_TAB_LINE_HEIGHT (w)