UBSan: index out of bounds for type 'OT::LongMetric const[1]' #761
Description
Found with commit 8cb8bfd using hb-fuzzer + UBSan
hb-ot-hmtx-table.hh:146:14: runtime error: index 48 out of bounds for type 'OT::LongMetric const[1]'
#0 0x56fdda in OT::hmtxvmtxOT::hmtx::accelerator_t::get_advance(unsigned int, hb_font_t*) const /src/./hb-ot-hmtx-table.hh:146:74
#1 0x558dc4 in hb_ot_get_glyph_h_advance(hb_font_t*, void*, unsigned int, void*) /src/hb-ot-font.cc:120:47
#2 0x635c0a in hb_ot_position_default(hb_ot_shape_context_t*) /src/hb-ot-shape.cc:676:35
#3 0x635c0a in hb_ot_position(hb_ot_shape_context_t*) /src/hb-ot-shape.cc:774
#4 0x635c0a in hb_ot_shape_internal(hb_ot_shape_context_t*) /src/hb-ot-shape.cc:860
#5 0x631e3d in _hb_ot_shape /src/hb-ot-shape.cc:887:3
#6 0x550059 in hb_shape_plan_execute /src/./hb-shaper-list.hh:43:1
#7 0x54e6f1 in hb_shape_full /src/hb-shape.cc:132:19
#8 0x510b56 in LLVMFuzzerTestOneInput /test/fuzzing/hb-fuzzer.cc:30:5
#9 0x5117e7 in main /test/fuzzing/main.cc:20:4
#10 0x7f71968b682f in __libc_start_main /build/glibc-Cl5G7W/glibc-2.23/csu/../csu/libc-start.c:291
#11 0x41a948 in _start (hb-fuzzer+0x41a948)