[pango] Add a runtime version check for harfbuzz

[Matthias Clasen <matthiasc src gnome org>]

commit fb72c7dd3e074f28e7cfa98388a87f1aaffc12ee
Author: Matthias Clasen <mclasen redhat com>
Date:   Mon Aug 19 14:23:55 2019 +0200

    Add a runtime version check for harfbuzz
    
    Electron apps seem to include a static copy of a
    too old version of harfbuzz. Error out with a clear
    message in this broken situation, instead of
    segfaulting later.

 pango/pangofc-fontmap.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
---
diff --git a/pango/pangofc-fontmap.c b/pango/pangofc-fontmap.c
index 2bda526e..c7193941 100644
--- a/pango/pangofc-fontmap.c
+++ b/pango/pangofc-fontmap.c
@@ -2752,11 +2752,14 @@ pango_fc_font_map_get_hb_face (PangoFcFontMap *fcfontmap,
   PangoFcFontFaceData *data;
 
   data = pango_fc_font_map_get_font_face_data (fcfontmap, fcfont->font_pattern);
-  
+
   if (!data->hb_face)
     {
       hb_blob_t *blob;
 
+      if (!hb_version_atleast (2, 0, 0))
+        g_error ("Harfbuzz version too old (%s)\n", hb_version_string ());
+
       blob = hb_blob_create_from_file (data->filename);
       data->hb_face = hb_face_create (blob, data->id);
       hb_blob_destroy (blob);