Fix rendering of HTML pages that use character composition

* src/indent.c (Fvertical_motion): Fix the case when point starts
in the middle of a composition, as in shr-vertical-motion.
(Bug#22250)

1 files changed, 9 insertions, 0 deletions

diff --git a/src/indent.c b/src/indent.c
index 33bf424b344..ec38ea798c7 100644
--- a/src/indent.c
+++ b/src/indent.c
@@ -2130,6 +2130,15 @@ whether or not it is currently displayed in some window.  */)
               && it.method == GET_FROM_BUFFER
               && it.c == '\n')
             it_overshoot_count = 1;
+          else if (it_overshoot_count == 1 && it.vpos == 0
+                   && it.current_x < it.last_visible_x)
+            {
+              /* If we came to the same screen line as the one where
+                 we started, we didn't overshoot the line, and won't
+                 need to backtrack after all.  This happens, for
+                 example, when PT is in the middle of a composition.  */
+              it_overshoot_count = 0;
+            }
           else if (disp_string_at_start_p && it.vpos > 0)
             {
               /* This is the case of a display string that spans