[kern] Fix invalid memory access if offset is zero
authorBehdad Esfahbod <behdad@behdad.org>
Fri, 10 Nov 2017 02:09:40 +0000 (18:09 -0800)
committerBehdad Esfahbod <behdad@behdad.org>
Fri, 10 Nov 2017 02:09:40 +0000 (18:09 -0800)
commit8eed9cb11e28728a58e265fde5c13f519ccbdb4e
treea811b1bf15bf9836f25fa5382ebe399ff8d73858
parentb68fba4dc81ce2e7552c5d50a93013281889a65b
[kern] Fix invalid memory access if offset is zero

If offset is zero, we return Null() object.  Wasn't prepared for that.

Fixes https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=4088
src/hb-ot-kern-table.hh
test/shaping/fonts/sha1sum/243798dd281c1c77c065958e1ff467420faa9bde.ttf [new file with mode: 0644]
test/shaping/tests/fuzzed.tests