Currently COLRv1 spec is being changed so the subsetting implementation is out of sync. Disable subsetting by failing sanitization for COLRv1 tables and disable all colrv1 tests.
Fixing these complains raised by newer versions of clang,
./hb-ot-layout-common.hh:1720:53: error: loop variable 'gid_klass_pair' is always a copy because the range of type 'hb_map_iter_t<hb_sorted_array_t<OT::HBGlyphID>, (lambda at ./hb-ot-layout-common.hh:1672:29), hb_function_sortedness_t::RETAINS_SORTING, nullptr>' does not return a reference [-Werror,-Wrange-loop-analysis]
for (const hb_pair_t<hb_codepoint_t, unsigned>& gid_klass_pair : + it)
And
./hb-ot-color-colr-table.hh:177:44: error: loop variable '_' is always a copy because the range of type 'hb_map_iter_t<hb_filter_iter_t<hb_map_iter_t<hb_range_iter_t<unsigned int, unsigned int>, (lambda at ./hb-ot-color-colr-table.hh:209:31), hb_function_sortedness_t::RETAINS_SORTING, nullptr>, (anonymous struct at ./hb-algs.hh:331:1) &, (anonymous struct at ./hb-algs.hh:51:1) &, nullptr>, (anonymous struct at ./hb-algs.hh:338:1) &, hb_function_sortedness_t::RETAINS_SORTING, nullptr>' does not return a reference [-Werror,-Wrange-loop-analysis]
for (const hb_item_type<BaseIterator>& _ : + base_it.iter ())
COLR table has one function: return layers for a glyph, and we expose exactly
that, so should just wire it through. Also use sub_array() for verifiable
safety.
Also, BaseGlyphRecord's null object is enough. We don't need to special-case
the not-found.
...like UnsizedArrayOf<>.
This fixes a class of crasher bugs, mostly with color and AAT tables. We
cannot use nullable offsets to varsized data that does not declare min_size,
because it's nost safe to use our fixed-size null pool for types that have
their size external. So, use non_null'able offsets for these.
A further enhancement would be to make use of min_size in Null<> itself.
Will try that after.