master 38b4bbb7e1: A cleaner fix for display bug#52947

[Eli Zaretskii]

branch: master
commit 38b4bbb7e1abaa9f925048840b53290e2011a851
Author: Eli Zaretskii <eliz@gnu.org>
Commit: Eli Zaretskii <eliz@gnu.org>

    A cleaner fix for display bug#52947
    
    * src/xdisp.c (tab_bar_height, redisplay_tab_bar): Don't call
    set_iterator_to_next here...
    (display_tab_bar_line): ...call it here, even if we exit the loop
    because we encounter a newline.
---
 src/xdisp.c | 16 +++++-----------
 1 file changed, 5 insertions(+), 11 deletions(-)

diff --git a/src/xdisp.c b/src/xdisp.c
index 6e94ff5ec6..0635cad0d1 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -13745,6 +13745,7 @@ display_tab_bar_line (struct it *it, int height)
      so there's no need to check the face here.  */
   it->start_of_box_run_p = true;
 
+  bool enough = false;
   while (it->current_x < max_x)
     {
       int x, n_glyphs_before, i, nglyphs;
@@ -13791,11 +13792,12 @@ display_tab_bar_line (struct it *it, int height)
          ++i;
        }
 
+      enough = ITERATOR_AT_END_OF_LINE_P (it);
+      set_iterator_to_next (it, true);
+
       /* Stop at line end.  */
-      if (ITERATOR_AT_END_OF_LINE_P (it))
+      if (enough)
        break;
-
-      set_iterator_to_next (it, true);
     }
 
  out:;
@@ -13878,10 +13880,6 @@ tab_bar_height (struct frame *f, int *n_rows, bool 
pixelwise)
     {
       it.glyph_row = temp_row;
       display_tab_bar_line (&it, -1);
-      /* If the tab-bar string includes newlines, get past it, because
-        display_tab_bar_line doesn't.  */
-      if (ITERATOR_AT_END_OF_LINE_P (&it))
-       set_iterator_to_next (&it, true);
     }
   clear_glyph_row (temp_row);
 
@@ -14007,10 +14005,6 @@ redisplay_tab_bar (struct frame *f)
              extra -= h;
            }
          display_tab_bar_line (&it, height + h);
-         /* If the tab-bar string includes newlines, get past it,
-            because display_tab_bar_line doesn't.  */
-         if (ITERATOR_AT_END_OF_LINE_P (&it))
-           set_iterator_to_next (&it, true);
        }
     }
   else