[pango/fix-keycap-sequences: 19/20] Fix handling of keycap sequences

[Matthias Clasen <matthiasc src gnome org>]

commit b1718281f02fa811bcff7ef7a73ee361c452747b
Author: Matthias Clasen <mclasen redhat com>
Date:   Thu Sep 17 19:17:27 2020 -0400

    Fix handling of keycap sequences
    
    The last character of Emoji keycap sequences, 0x20E3,
    has a vertical orientation of U, according to Unicode.
    This unfortunately makes the width iter frequently break
    such sequences into multiple items, preventing them from
    being rendered as expected.
    
    Fix this by ignoring width changes inside Emoji sequences.
    
    Fixes: #502

 pango/pango-context.c | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)
---
diff --git a/pango/pango-context.c b/pango/pango-context.c
index bebe804a..1fcdf366 100644
--- a/pango/pango-context.c
+++ b/pango/pango-context.c
@@ -1065,6 +1065,9 @@ itemize_state_init (ItemizeState      *state,
   width_iter_init (&state->width_iter, text + start_index, length);
   _pango_emoji_iter_init (&state->emoji_iter, text + start_index, length);
 
+  if (state->emoji_iter.is_emoji)
+    state->width_iter.end = MAX (state->width_iter.end, state->emoji_iter.end);
+
   update_end (state);
 
   if (pango_font_description_get_set_fields (state->font_desc) & PANGO_FONT_MASK_GRAVITY)
@@ -1111,15 +1114,18 @@ itemize_state_next (ItemizeState *state)
                                   &state->script_end, &state->script);
       state->changed |= SCRIPT_CHANGED;
     }
-  if (state->run_end == state->width_iter.end)
-    {
-      width_iter_next (&state->width_iter);
-      state->changed |= WIDTH_CHANGED;
-    }
   if (state->run_end == state->emoji_iter.end)
     {
       _pango_emoji_iter_next (&state->emoji_iter);
       state->changed |= EMOJI_CHANGED;
+
+      if (state->emoji_iter.is_emoji)
+        state->width_iter.end = MAX (state->width_iter.end, state->emoji_iter.end);
+    }
+  if (state->run_end == state->width_iter.end)
+    {
+      width_iter_next (&state->width_iter);
+      state->changed |= WIDTH_CHANGED;
     }
 
   update_end (state);