Fonttools

----------------------------

- [colorLib/otData] Updated to latest draft ``COLR`` v1 spec (2092).
- [svgLib] Fixed parsing error when arc commands' boolean flags are not separated
by space or comma (2094).
- [varLib] Interpret empty non-default glyphs as 'missing', if the default glyph is
not empty (2082).
- [feaLib.builder] Only stash lookup location for ``Debg`` if ``Builder.buildLookups_``
has cooperated (2065, 2067).
- [varLib] Fixed bug in VarStore optimizer (2073, 2083).
- [varLib] Add designspace lib key for custom feavar feature tag (2080).
- Add HashPointPen adapted from psautohint. With this pen, a hash value of a glyph
can be computed, which can later be used to detect glyph changes (2005).

----------------------------

- [varLib.instancer] Fixed ``TypeError`` exception when instantiating a VF with
a GSUB table 1.1 in which ``FeatureVariations`` attribute is present but set to
``None`` -- indicating that optional ``FeatureVariations`` is missing (2077).
- [glifLib] Make ``x`` and ``y`` attributes of the ``point`` element required
even when validation is turned off, and raise a meaningful ``GlifLibError``
message when that happens (2075).

----------------------------

- [removeOverlaps] Added new module and ``removeOverlaps`` function that merges
overlapping contours and components in TrueType glyphs. It requires the
`skia-pathops <https://github.com/fonttools/skia-pathops>`__ module.
Note that removing overlaps invalidates the TrueType hinting (2068).
- [varLib.instancer] Added ``--remove-overlaps`` command-line option.
The ``overlap`` option in ``instantiateVariableFont`` now takes an ``OverlapMode``
enum: 0: KEEP_AND_DONT_SET_FLAGS, 1: KEEP_AND_SET_FLAGS (default), and 2: REMOVE.
The latter is equivalent to calling ``removeOverlaps`` on the generated static
instance. The option continues to accept ``bool`` value for backward compatibility.

----------------------------

- [plistlib] Added typing annotations to plistlib module. Set up mypy static
typechecker to run automatically on CI (2061).
- [ttLib] Implement private ``Debg`` table, a reverse-DNS namespaced JSON dict.
- [feaLib] Optionally add an entry into the ``Debg`` table with the original
lookup name (if any), feature name / script / language combination (if any),
and original source filename and line location. Annotate the ttx output for
a lookup with the information from the Debg table (2052).
- [sfnt] Disabled checksum checking by default in ``SFNTReader`` (2058).
- [Docs] Document ``mtiLib`` module (2027).
- [varLib.interpolatable] Added checks for contour node count and operation type
of each node (2054).
- [ttLib] Added API to register custom table packer/unpacker classes (2055).

----------------------------

- [feaLib] Allow anonymous classes in LookupFlags definitions (2037).
- [Docs] Better document DesignSpace rules processing order (2041).
- [ttLib] Fixed 21-year old bug in ``maxp.maxComponentDepth`` calculation (2044,
2045).
- [varLib.models] Fixed misspelled argument name in CLI entry point (81d0042a).
- [subset] When subsetting GSUB v1.1, fixed TypeError by checking whether the
optional FeatureVariations table is present (e63ecc5b).
- [Snippets] Added snippet to show how to decompose glyphs in a TTF (2030).
- [otlLib] Generate GSUB type 5 and GPOS type 7 contextual lookups where appropriate
(2016).

----------------------------

- [feaLib/otlLib] Moved lookup subtable builders from feaLib to otlLib; refactored
some common code (2004, 2007).
- [docs] Document otlLib module (2009).
- [glifLib] Fixed bug with some UFO .glif filenames clashing on case-insensitive
filesystems (2001, 2002).
- [colorLib] Updated COLRv1 implementation following changes in the draft spec:
(2008, googlefonts/colr-gradients-spec24).