Sync with 4.0.1

[LaurenzV]

Status	Commit message	HB	Comments
⚪️	[ci] Downgrade pip on MSVC jobs	Link
🟢	[arabic] Update to AMTRA revision 6	Link
🟢	[ot-tag] Add HB_SCRIPT_MATH (Zmth) and map it to OT ‚Äòmath‚Äô tag	Link
⚪️	Revert "[ci] Downgrade pip on MSVC jobs"	Link
⚪️	[ot-math] Add hb_ot_math_get_glyph_kernings	Link
⚪️	[ci] Upgrade pip on MSVC job	Link
⚪️	hb-algs.hh: Fix build on Visual Studio 2015	Link
⚪️	meson.build: Only use get_variable() on icu_dep with pkgconfig	Link
⚪️	[machinery] Allow using lazy-loader with void*	Link
⚪️	[subset] Add subset plan to public API.	Link
⚪️	[subset] add subset plan reference	Link
⚪️	[subset] Change subset plan create to be or_fail.	Link
⚪️	[subset] Fix memory leak in plan creation.	Link
⚪️	Add a fuzzer font	Link
⚪️	[hmtx] Remove one subset-specific method from hmtx accelerator	Link
⚪️	[hmtx] Remove other subset-specific method from hmtx accelerator	Link
⚪️	[test/subset] Don't hash files without reason	Link
⚪️	Merge pull request #3398 from harfbuzz/buffer-verify	Link
⚪️	[name] Extraneous (out) annotation in return value	Link
⚪️	3.4.0	Link
⚪️	Typo	Link
⚪️	[ci] Add configs-ci.yml to test different configs	Link
⚪️	Fix compiler warning	Link
⚪️	[draw] Remove EXPERIMENTAL_API tag	Link
⚪️	[font] Add em_scaleff() that returns float	Link
⚪️	[font] Add em_fscalef_[xy] That take and return float	Link
⚪️	[draw] Convert API to float instead of hb_position_t	Link
⚪️	[main] Fix compiler warnings	Link
⚪️	[draw] Replace API Since tags with REPLACEME	Link
⚪️	[draw] Move hb_font_draw_glyph() to hb-draw-glyph.cc	Link
⚪️	[draw] Remove return value of hb_font_draw_glyph()	Link
⚪️	[draw] Whitespace	Link
⚪️	[draw] Another Since: tag update	Link
⚪️	[test-draw] Fix compiler warning	Link
⚪️	[draw] Enable draw tests	Link
⚪️	Remove remaining traces of HB_EXPERIMENTAL_API	Link
⚪️	[draw-fuzzer] Fix signatures	Link
⚪️	[draw] Fix draw signatures	Link
⚪️	[draw] Remove unneeded roundf() calls	Link
⚪️	[draw] Rename user_data to draw_data	Link
⚪️	[draw] Virtualize hb_font_draw_glyph() into hb_font_get_glyph_shape()	Link
⚪️	[draw] Add REPLACEME	Link
⚪️	[draw] Add TODO	Link
⚪️	[test-draw] Re-enable two disabled tests	Link
⚪️	[draw-state] Add type and use in draw-helper	Link
⚪️	[draw] Remove check for no-op	Link
⚪️	[draw] Simplify start_path	Link
⚪️	[draw] Rename internal methods	Link
⚪️	[test-draw] Fix compiler warning	Link
⚪️	[draw] Add public move_to/line_to/... API that take a draw-state	Link
⚪️	[draw-state] Pass state down to callbacks	Link
⚪️	[draw] Rename internal draw_helper_t to draw_session_t	Link
⚪️	[draw] Do quadratic-to-cubic conversion in nil quadratic implementation	Link
⚪️	[util] Use hb-draw to render alternatively to cairo-ft	Link
⚪️	[draw] Rename internal draw_session_t to hb_draw_session_t	Link
⚪️	[ft/draw] Implement hb-draw for hb-ft	Link
⚪️	[util/draw/ft] Use hb-draw for font-funcs=ft as well	Link
⚪️	[util/draw] Render color glyphs if cairo API available	Link
⚪️	[draw] Minor cleanup	Link
⚪️	[font/draw] Fetch shape from parent font if not implemented in font	Link
⚪️	[draw] Add more reserved items to hb_draw_state_t	Link
⚪️	[draw-session] Add slant	Link
⚪️	[font/draw] Slant drawings	Link
⚪️	[util] Add --font-slant	Link
⚪️	[font] Adjust synthetic-slant docs	Link
⚪️	[font] Update get_glyph_shape() doc	Link
⚪️	[draw] Flesh out docs a bit	Link
⚪️	[draw] Document more	Link
⚪️	[util/draw] Apply slant to non-user-fonts as well	Link
⚪️	[draw] Destroy callback data	Link
⚪️	[meson] fix building with Cairo subproject	Link
⚪️	[doc] Message draw documentation a bit	Link
⚪️	[meson] Put back Experimental-API infrastructure	Link
⚪️	[doc] Document HB_DRAW_STATE_DEFAULT	Link
⚪️	[doc] Link to respective draw callback functions	Link
⚪️	[meson] Update cairo subproject	Link
⚪️	[draw] Implement COLRv0 fonts	Link
⚪️	[draw] Fix conversion warnings	Link
⚪️	[util/draw] Use hb-draw in hb-view only if HB_DRAW=1	Link
⚪️	[util/draw] Explicitly chain from render_color_glyph to render_glyph	Link
⚪️	[util/draw] If HB_DRAW is not set	Link
⚪️	[util] Default font-funcs to 'ot' instead of 'ft'	Link
⚪️	[draw] Add test for hb_draw_move_to() etc	Link
⚪️	[draw] Add test for applying synthetic slant	Link
⚪️	[draw] Emit move_to immediately	Link
⚪️	[draw] Another try at a stable draw moveto semantic	Link
⚪️	[util] Implement --sub-font	Link
⚪️	[draw] Test scaling subfont differently from parent	Link
⚪️	[draw/glyf] Don't skip empty contours of size 2	Link
⚪️	[meson] Update cairo submodule	Link
⚪️	[draw] Fix some introspection warnings	Link
⚪️	[algs] Fix typo in hb_pair_t conversion operator	Link
⚪️	[draw/glyf] Emit empty contours	Link
⚪️	[draw/test] Add test for freetype callback	Link
⚪️	[test/draw] Typo	Link
⚪️	[draw/test] Swap a freetype test case with a simpler one	Link
⚪️	[meson] Update Cairo subproject	Link
⚪️	Remove return of void	Link
⚪️	[ot-face] Load num-glyphs from `loca` table before `maxp`	Link
⚪️	[hmtx] Internal rename num_metrics to num_bearings	Link
⚪️	[hmtx] Rename internal num_advances to num_long_metrics	Link
⚪️	[hmtx] Document	Link
⚪️	[test] Add test for current hmtx logic	Link
⚪️	[hmtx] Implement [boring-expansion] >64k expansion	Link
⚪️	Fix build	Link
⚪️	[test/api] Fix leaks	Link
⚪️	[ci] Rename configs-ci to configs-build	Link
⚪️	[test/shape] Internal rename	Link
⚪️	[config] Add HB_NO_BORING_EXPANSION	Link
⚪️	[machinery] Add "core table" machinery	Link
⚪️	[ot-face] Use core tables	Link
	[face] Use max numGlyphs of maxp and loca	Link
⚪️	Merge pull request #3411 from harfbuzz/draw	Link
⚪️	Improve docs for hb_ot_layout_get_ligature_carets	Link
⚪️	[autotools] Fix make distcheck	Link
⚪️	[ot-layout] Add +hb_ot_layout_get_horizontal_baseline_tag_for_script()	Link
⚪️	Merge pull request #3410 from harfbuzz/boring-expansion	Link
⚪️	[ot-layout] Remove commented-out prototypes	Link
⚪️	[ot-layout] Synthesize missing baselines	Link
⚪️	[ot-layout] Add central baselines	Link
⚪️	meson: Cleanup finding FreeType on Visual Studio	Link
⚪️	meson: Clean up finding ICU-UC on Visual Studio	Link
⚪️	freetype2.wrap: Provide fallback for CMake dep as well	Link
⚪️	BUILD.md: Mention that installing CMake is recommended for MSVC	Link
⚪️	Merge pull request #3449 from fanc999/msvc-meson-use-cmake	Link
⚪️	Revert "hb-algs.hh: Fix build on Visual Studio 2015"	Link
⚪️	Merge pull request #3437 from matthiasclasen/synthesize-missing-baselines	Link
⚪️	[ot-metrics] Synthesize missing metrics	Link
⚪️	[subset] document return values.	Link
⚪️	[util] Rename template typenames to avoid clashing with actual types	Link
🟢	[buffer] Add HB_BUFFER_FLAG_PRODUCE_UNSAFE_TO_CONCAT	Link
⚪️	[hb-style] Fix synthetic slant values	Link
⚪️	[hb-style] Fix the sign of slant ratios	Link
⚪️	[style] Move the negation into the constant	Link
⚪️	Add a missing file	Link
⚪️	[meson] handle multiple element ICU DEFS	Link
⚪️	Merge pull request #3459 from jameshilliard/icu-defs-mutliarg	Link
⚪️	Merge pull request #3429 from harfbuzz/external_plan	Link
⚪️	Merge pull request #3423 from harfbuzz/revert-ci-msvc	Link
⚪️	[doc] Various fixes to newly added documentation	Link
⚪️	[subset] Rename codepoint -> unicode in subset plan api	Link
⚪️	[doc] Typo	Link
⚪️	4.0.0	Link
⚪️	Minor [ci skip]	Link
⚪️	Fixed various misc. typos	Link
⚪️	Merge pull request #3464 from luzpaz/typos	Link
🟢	[aat] Update OT to AAT mappings for hist and vrtr	Link
🟢	[USE] Restore the category WJ	Link
🟢	[USE] Allow any non-numeric tail in symbol cluster	Link
🟢	[USE] Simplify `not_ccs_default_ignorable`	Link
🟢	[USE] Remove obsolete symbol/punctuation overrides	Link
🟢	[USE] Treat all gc=Cn as independent clusters	Link
🟢	[USE] Remove obsolete overrides	Link
🟢	Update IANA Language Subtag Registry to 2022-03-02	Link
⚪️	[layout] Fix handling of baseline variations	Link
⚪️	[repacker] expose hb_subset_repack() API	Link
⚪️	[doc] Add experimental repacker API to private section	Link
⚪️	4.0.1	Link

[LaurenzV]

Most changes were irrelevant, because a lot of them are for the draw API which don't matter for us (right?).

There were a couple of changes which I think belong to ttf-parser, but I still marked them as orange so you can take a quick look because I want to err on the side of caution, so this time there are more commits marked as orange, but a lot of them depend on each other.

P.S: I tried to port to 4.1 as well so that we're straight at the reorg commits, but the commit directly after introduces changes to the ragel machine which makes it look different and it doesn't compile anymore, and I don't know how it works... So I think someone who knows how it works will have to take a stab at that one.

[RazrFalcon]

Most changes were irrelevant, because a lot of them are for the draw API which don't matter for us (right?).

Yep. We have ttf-parser for that.

commit directly after introduces changes to the ragel machine which makes it look different and it doesn't compile anymore

You mean rl files were changed and ragel cannot produce Rust code anymore?

[ot-math] Add hb_ot_math_get_glyph_kernings

Not sure about now, but when I was originally porting harfbuzz, the MATH table wasn't used during shaping.
And the only reason it is present in ttf-parser is because someone needed it. But rustybuzz doesn't use it.

Once again, harfbuzz isn't just a shaper, it's a collection of things. rustybuzz just a shaper.

[font] Add em_scaleff() that returns float

Irrelevant. We do not support font scaling. For better or worse.
There are some edge cases and quirks, but in most cases it can be done by the caller it whatever way it wants.

[draw-session] Add slant

Irrelevant.

[ot-face] Load num-glyphs from loca table before maxp
[face] Use max numGlyphs of maxp and loca

Irrelevant. It's a ttf-parser problem to handle malformed fonts.

[hmtx] Internal rename num_metrics to num_bearings
[hmtx] Rename internal num_advances to num_long_metrics

Irrelevant. TrueType parsing is out of the scope unless tests are failing.

[hmtx] Implement [boring-expansion] >64k expansion

There are no plans to support TrueType extensions.

[ot-layout] Add +hb_ot_layout_get_horizontal_baseline_tag_for_script()
[ot-layout] Synthesize missing baselines
[ot-layout] Add central baselines
[ot-metrics] Synthesize missing metrics

Irrelevant. rustybuzz only does shaping. It has no font info getters.

[LaurenzV]

You mean rl files were changed and ragel cannot produce Rust code anymore?

I can still produce Rust code. But the Rust code now looks a lot different and just changing "0" to "p0" doesn't fix it anymore, there's more broken stuff in there. If you want I can make a separate branch with just that one commit to demonstrate.

Once again, harfbuzz isn't just a shaper, it's a collection of things. rustybuzz just a shaper.

Yeah, I know. :p But sometimes I'm still a bit unsure so I'd rather just ask instead of straight up ignoring it, I hope you don't mind. If you do then I can also try to trust my "intuition" more in the future.

[LaurenzV]

There are no plans to support TrueType extensions.

So all of the >64k expansion commits can probably be ignored for the future?

[RazrFalcon]

Then the only way is to send a bugreport to ragel, but it's kinda dead, so what's the point... In the worst case scenario we could fallback to manual C to Rust code conversion, as it was done originally.

Yeah, I know. :p But sometimes I'm still a bit unsure so I'd rather just ask instead of straight up ignoring it, I hope you don't mind. If you do then I can also try to trust my "intuition" more in the future.

You can still ask if unsure, I don't mind. Again, all I care about it that tests are passing.

So all of the >64k expansion commits can probably be ignored for the future?

Yes, we're not interested in this. Those changes are not part of the TrueType spec.

[LaurenzV]

I guess for 4.0.1 this should be complete then.

[LaurenzV]

Okay I made some more manual changes to the machine and it seems like it works, including the new test cases that were added. So maybe I will try all of 4.1 tomorrow. Don't seem to be too many commits anyway, but no promises.

But we can still merge 4.0.1 as is, I think.

[RazrFalcon]

Thanks!