master 67e7870a62: Fix mouse clicks in hscrolled window with variable-height fonts

[Eli Zaretskii]

branch: master
commit 67e7870a621aacd8fd5d096fe673d86cc1f3a0f5
Author: Eli Zaretskii <eliz@gnu.org>
Commit: Eli Zaretskii <eliz@gnu.org>

    Fix mouse clicks in hscrolled window with variable-height fonts
    
    * src/xdisp.c (move_it_in_display_line_to): Fix calculation of
    height of a screen-line that is completely hscrolled out of view.
    Reported by Yasushi SHOJI <yasushi.shoji@gmail.com>.
---
 src/xdisp.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/src/xdisp.c b/src/xdisp.c
index 6a0d0ea879..2dbc68f657 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -9910,6 +9910,18 @@ move_it_in_display_line_to (struct it *it,
            }
          else
            result = MOVE_NEWLINE_OR_CR;
+         /* If lines are truncated, and the line we moved across is
+            completely hscrolled out of view, reset the line metrics
+            to those of the newline we've just processed, so that
+            glyphs not on display don't affect the line's height.  */
+         if (it->line_wrap == TRUNCATE
+             && it->current_x <= it->first_visible_x
+             && result == MOVE_NEWLINE_OR_CR
+             && it->char_to_display == '\n')
+           {
+             it->max_ascent = it->ascent;
+             it->max_descent = it->descent;
+           }
          /* If we've processed the newline, make sure this flag is
             reset, as it must only be set when the newline itself is
             processed.  */