[ot-color/png] Try to get image blob from sbix first options.aat is set

src/hb-ot-color.cc

@@ -310,15 +310,21 @@ hb_ot_color_glyph_reference_blob_png (hb_font_t      *font,
 				      unsigned int   *strike_x_ppem /* OUT */,
 				      unsigned int   *strike_y_ppem /* OUT */)
 {
-  if (_get_cbdt (font->face).has_data ())
-    return _get_cbdt (font->face).reference_blob_for_glyph (glyph, font->x_ppem, font->y_ppem,
+  hb_blob_t *blob = hb_blob_get_empty ();
+  /* don't run cbdt first if aat is set */
+  if (!hb_options ().aat && _get_cbdt (font->face).has_data ())
+    blob = _get_cbdt (font->face).reference_blob_for_glyph (glyph, font->x_ppem, font->y_ppem,
 							    strike_x_ppem, strike_y_ppem);
 
-  if (_get_sbix (font->face).has_data ())
-    return _get_sbix (font->face).reference_blob_for_glyph (glyph, font->ptem,
+  if (_get_sbix (font->face).has_data () && !hb_blob_get_length (blob))
+    blob = _get_sbix (font->face).reference_blob_for_glyph (glyph, font->ptem,
 							    MAX (font->x_ppem, font->y_ppem),
 							    HB_TAG('p','n','g',' '),
 							    strike_x_ppem, strike_y_ppem);
 
-  return hb_blob_get_empty ();
+  if (hb_options ().aat && _get_cbdt (font->face).has_data () && !hb_blob_get_length (blob))
+    blob = _get_cbdt (font->face).reference_blob_for_glyph (glyph, font->x_ppem, font->y_ppem,
+							    strike_x_ppem, strike_y_ppem);
+
+  return blob;
 }