Comment 3 for bug 930541

StacktraceTop:
 operator uint16_t (this=0x7f722ad3f6bf) at /build/buildd/pango1.0-1.29.5/./pango/opentype/hb-open-type-private.hh:373
 operator[] (this=0x7f722ad3f6bf, i=0) at /build/buildd/pango1.0-1.29.5/./pango/opentype/hb-open-type-private.hh:504
 operator[] (this=0x7f722ad3f6bf, i=0) at /build/buildd/pango1.0-1.29.5/./pango/opentype/hb-ot-layout-common-private.hh:109
 get_feature (i=0, this=<optimized out>) at /build/buildd/pango1.0-1.29.5/./pango/opentype/hb-ot-layout-gsubgpos-private.hh:927
 hb_ot_layout_feature_get_lookup_indexes (face=<optimized out>, table_tag=<optimized out>, feature_index=0, lookup_count=0x7fff2de8423c, lookup_indexes=0x7fff2de83290) at /build/buildd/pango1.0-1.29.5/./pango/opentype/hb-ot-layout.cc:509