[Emacs-diffs] emacs-24 r117417: Fix display of R2L lines when the last character fits only partially.

[Eli Zaretskii]

------------------------------------------------------------
revno: 117417
revision-id: address@hidden
parent: address@hidden
committer: Eli Zaretskii <address@hidden>
branch nick: emacs-24
timestamp: Fri 2014-08-01 12:39:04 +0300
message:
  Fix display of R2L lines when the last character fits only partially.
  
   See http://lists.gnu.org/archive/html/emacs-devel/2014-07/msg00476.html
   for the details.
   src/xdisp.c (extend_face_to_end_of_line): If the last glyph of an
   R2L row is visible only partially, give the row a negative x
   offset.
   (display_line): Fix the calculation of the glyph whose pixel width
   is used to decide whether the last produced glyph fits on the
   line.  When the last glyph fits only partially, give the row a
   negative x offset.
modified:
  src/ChangeLog                  changelog-20091113204419-o5vbwnq5f7feedwu-1438
  src/xdisp.c                    xdisp.c-20091113204419-o5vbwnq5f7feedwu-240

=== modified file 'src/ChangeLog'
--- a/src/ChangeLog     2014-07-29 08:19:29 +0000
+++ b/src/ChangeLog     2014-08-01 09:39:04 +0000
@@ -1,3 +1,16 @@
+2014-08-01  Eli Zaretskii  <address@hidden>
+
+       Fix display of R2L lines when the last character fits only partially.
+       See http://lists.gnu.org/archive/html/emacs-devel/2014-07/msg00476.html
+       for the details.
+       * xdisp.c (extend_face_to_end_of_line): If the last glyph of an
+       R2L row is visible only partially, give the row a negative x
+       offset.
+       (display_line): Fix the calculation of the glyph whose pixel width
+       is used to decide whether the last produced glyph fits on the
+       line.  When the last glyph fits only partially, give the row a
+       negative x offset.
+
 2014-07-29  Eli Zaretskii  <address@hidden>
 
        Fix hscroll of R2L lines that begin with a TAB or another wide glyph.

=== modified file 'src/xdisp.c'
--- a/src/xdisp.c       2014-07-29 08:19:29 +0000
+++ b/src/xdisp.c       2014-08-01 09:39:04 +0000
@@ -19316,6 +19316,12 @@
              it->face_id = saved_face_id;
              it->start_of_box_run_p = saved_box_start;
            }
+         /* If stretch_width comes out negative, it means that the
+            last glyph is only partially visible.  In R2L rows, we
+            want the leftmost glyph to be partially visible, so we
+            need to give the row the corresponding left offset.  */
+         if (stretch_width < 0)
+           it->glyph_row->x = stretch_width;
        }
 #endif /* HAVE_WINDOW_SYSTEM */
     }
@@ -20207,7 +20213,13 @@
 
          for (i = 0; i < nglyphs; ++i, x = new_x)
            {
-             glyph = row->glyphs[TEXT_AREA] + n_glyphs_before + i;
+             /* Identify the glyphs added by the last call to
+                PRODUCE_GLYPHS.  In R2L rows, they are prepended to
+                the previous glyphs.  */
+             if (!row->reversed_p)
+               glyph = row->glyphs[TEXT_AREA] + n_glyphs_before + i;
+             else
+               glyph = row->glyphs[TEXT_AREA] + nglyphs - 1 - i;
              new_x = x + glyph->pixel_width;
 
              if (/* Lines are continued.  */
@@ -20415,6 +20427,12 @@
                       suitable change to the stretch glyph that is
                       the leftmost glyph of the line.  */
                    row->x = x - it->first_visible_x;
+                 /* When the last glyph of an R2L row only fits
+                    partially on the line, we need to set row->x to a
+                    negative offset, so that the leftmost glyph is
+                    the one that is partially visible.  */
+                 if (row->reversed_p && new_x > it->last_visible_x)
+                   row->x = it->last_visible_x - new_x;
                }
              else
                {