They aren't contributing to rendering and making issue for stroking, let's skip them
ourselves as Skia does also https://skia-review.googlesource.com/c/skia/+/268166
They are useful for extracting extents and so which that functionality won't be effected by this change.
Specially checks correctness of the API semantics:
* no move happens when a path is already opened with move-to.
* no path will be left open and close-path will happen at the end of opened paths.
* no path opens with a move-to and will be closed with no length.
* paths start and ending points matches.
* no line/quadratic/cubic command will be issued when no path is started.
Newer versions of MSVC with /we4146 don't like putting negative sign behind a
unsigned number as https://github.com/harfbuzz/harfbuzz/pull/2069
That however have made https://crbug.com/1050424 this complain:
src/hb-ot-color-sbix-table.hh:304:28: runtime error: negation of -2147483648 cannot be represented in type 'int';
cast to an unsigned type to negate this value to itself
which apparently can be fixed using this change.
Let's see if this won't make another ubsan complain!
If a process operation results in less pages then the current set has, it will likely corrupt the page_map since it overwrites page_map entries ahead of where it's processing. This fixes that problem by removing page_map entries that will be dropped. Then dropping orphaned pages and re-indexing retained pages.
NotoColorEmoji.ttf uses two cmap subtables
Format 14 | Platform ID 0 | Platform Encoding ID 5
Format 12 | Platform ID 3 | Platform Encoding ID 10
This combination results in the cmap table being dropped during subsetting despite being valid/required.
This will fix inconsistency with fontTools.
Also according to the spec, namerecords must be sorted
first by platform ID, then by platform-specific ID,
then by language ID, and then by name ID.
Not all codepoints smaller than 0xFFFF go to cmap4 table.
Only subset codepoints existing in each table.
This will also make harfbuzz consistent with fontTools' behavior
