[pango] Protect against bugs in HarfBuzz's (non-)monotone cluster values

[Behdad Esfahbod <behdad src gnome org>]

commit 3f58b49182a117caadc0fcddeff39ce29ca8d397
Author: Behdad Esfahbod <behdad behdad org>
Date:   Tue Sep 1 16:40:34 2015 +0100

    Protect against bugs in HarfBuzz's (non-)monotone cluster values
    
    "Fixes" https://bugzilla.gnome.org/show_bug.cgi?id=541608
    
    Real fix went to HarfBuzz.

 pango/pango-glyph-item.c |    8 ++++----
 1 files changed, 4 insertions(+), 4 deletions(-)
---
diff --git a/pango/pango-glyph-item.c b/pango/pango-glyph-item.c
index 8c2cb4e..586b23b 100644
--- a/pango/pango-glyph-item.c
+++ b/pango/pango-glyph-item.c
@@ -281,7 +281,7 @@ pango_glyph_item_iter_next_cluster (PangoGlyphItemIter *iter)
              break;
            }
 
-         if (glyphs->log_clusters[glyph_index] != cluster)
+         if (glyphs->log_clusters[glyph_index] > cluster)
            {
              iter->end_index = item->offset + glyphs->log_clusters[glyph_index];
              iter->end_char += pango_utf8_strlen (iter->text + iter->start_index,
@@ -304,7 +304,7 @@ pango_glyph_item_iter_next_cluster (PangoGlyphItemIter *iter)
              break;
            }
 
-         if (glyphs->log_clusters[glyph_index] != cluster)
+         if (glyphs->log_clusters[glyph_index] > cluster)
            {
              iter->end_index = item->offset + glyphs->log_clusters[glyph_index];
              iter->end_char += pango_utf8_strlen (iter->text + iter->start_index,
@@ -372,7 +372,7 @@ pango_glyph_item_iter_prev_cluster (PangoGlyphItemIter *iter)
 
          glyph_index--;
 
-         if (glyphs->log_clusters[glyph_index] != cluster)
+         if (glyphs->log_clusters[glyph_index] < cluster)
            {
              glyph_index++;
              iter->start_index = item->offset + glyphs->log_clusters[glyph_index];
@@ -396,7 +396,7 @@ pango_glyph_item_iter_prev_cluster (PangoGlyphItemIter *iter)
 
          glyph_index++;
 
-         if (glyphs->log_clusters[glyph_index] != cluster)
+         if (glyphs->log_clusters[glyph_index] < cluster)
            {
              glyph_index--;
              iter->start_index = item->offset + glyphs->log_clusters[glyph_index];