[pango] Prevent HarfBuzz from using REPLACEMENT CHARACTER

[Behdad Esfahbod <behdad src gnome org>]

commit 9f67b924eb662f498f4e643ed740ce84640968f7
Author: Behdad Esfahbod <behdad behdad org>
Date:   Fri Jul 11 12:05:45 2014 -0400

    Prevent HarfBuzz from using REPLACEMENT CHARACTER
    
    Needed after this:
    https://github.com/behdad/harfbuzz/commit/efe74214bbb68eaa3d7621e73869b5d58210107e

 modules/basic/basic-fc.c |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)
---
diff --git a/modules/basic/basic-fc.c b/modules/basic/basic-fc.c
index 1ceaeab..93c4478 100644
--- a/modules/basic/basic-fc.c
+++ b/modules/basic/basic-fc.c
@@ -128,6 +128,12 @@ pango_fc_hb_font_get_glyph (hb_font_t *font, void *font_data,
     return TRUE;
 
   *glyph = PANGO_GET_UNKNOWN_GLYPH (unicode);
+
+  /* We draw our own invalid-Unicode shape, so prevent HarfBuzz
+   * from using REPLACEMENT CHARACTER. */
+  if (unicode > 0x10FFFF)
+    return TRUE;
+
   return FALSE;
 }