Disable more redisplay optimizations when child frames are visible

* src/xdisp.c (redisplay_internal): Disable more optimizations
on a tty root frame displaying a child frame.
(try_cursor_movement,(try_window_reusing_current_matrix)
(try_window_id): Don't use on tty root frames displaying a child frame.

(cherry picked from commit 07a2a67e3bfd674daad7a7d8947a0ab67b4e13e8)

diff --git a/src/xdisp.c b/src/xdisp.c
index f030628124aeaf5a19abdf86dfdebce94498dc55..48fc1b58ffa0e41de85a3a1ab02a5e502b0440f7 100644 (file)
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -17216,7 +17216,11 @@ redisplay_internal (void)
       /* All text outside that line, including its final newline,
         must be unchanged.  */
       && text_outside_line_unchanged_p (w, CHARPOS (tlbufpos),
-                                       CHARPOS (tlendpos)))
+                                       CHARPOS (tlendpos))
+      /* If this is a window on a tty root frame displaying a child frame,
+        the current matrix of W may contain glyphs of that child frame.
+        Don't try shortcuts that might use the current matrix in this case.  */
+      && !is_tty_root_frame_with_visible_child (XFRAME (w->frame)))
     {
       if (CHARPOS (tlbufpos) > BEGV
          && FETCH_BYTE (BYTEPOS (tlbufpos) - 1) != '\n'
@@ -17281,11 +17285,7 @@ redisplay_internal (void)
                 line and this line is the current one, because
                 display_line above is not informed about the
                 current-line's vpos, and cannot DTRT in that case.  */
-             && !hscrolling_current_line_p (w)
-             /* A root frame may have visible children displayed in its
-                current matrix, so that we can't do the below with its
-                current matrix.  */
-             && !is_tty_root_frame_with_visible_child (it.f))
+             && !hscrolling_current_line_p (w))
            {
              /* If this is not the window's last line, we must adjust
                 the charstarts of the lines below.  */
@@ -19432,6 +19432,13 @@ try_cursor_movement (Lisp_Object window, struct text_pos startp,
   struct frame *f = XFRAME (w->frame);
   int rc = CURSOR_MOVEMENT_CANNOT_BE_USED;
 
+
+  /* If this is a window on a tty root frame displaying a child frame,
+     the current matrix of W may contain glyphs of that child frame,
+     so this method is not safe to use.  */
+  if (is_tty_root_frame_with_visible_child (f))
+    return rc;
+
 #ifdef GLYPH_DEBUG
   if (inhibit_try_cursor_movement)
     return rc;
@@ -21335,6 +21342,13 @@ static bool
 try_window_reusing_current_matrix (struct window *w)
 {
   struct frame *f = XFRAME (w->frame);
+
+  /* If this is a window on a tty root frame displaying a child frame,
+     the current matrix of W may contain glyphs of that child frame,
+     so this method is not safe to use.  */
+  if (is_tty_root_frame_with_visible_child (f))
+    return false;
+
   struct glyph_row *bottom_row;
   struct it it;
   struct run run;
@@ -22122,6 +22136,13 @@ static int
 try_window_id (struct window *w)
 {
   struct frame *f = XFRAME (w->frame);
+
+  /* If this is a window on a tty root frame displaying a child frame,
+     the current matrix of W may contain glyphs of that child frame,
+     so this method is not safe to use.  */
+  if (is_tty_root_frame_with_visible_child (f))
+    return 0;
+
   struct glyph_matrix *current_matrix = w->current_matrix;
   struct glyph_matrix *desired_matrix = w->desired_matrix;
   struct glyph_row *last_unchanged_at_beg_row;