[woff2] Check whether known tag is in array bounds.

If table tag is not 0x3f, we expect a value between 0 and 62. If this is
not the case, exit with errors.

* src/sfnt/sfwoff2/c: Check whether table tag makes sense.

* src/sfnt/woff2tags.c: Return 0 if tag is out of bounds.
2 files changed