Fonttools

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

- [otBase] Make logging less verbose when harfbuzz fails to serialize. Do not exit
at the first failure but continue attempting to fix offset overflow error using
the pure-python serializer even when the ``USE_HARFBUZZ_REPACKER`` option was
explicitly set to ``True``. This is normal with fonts with relatively large
tables, at least until hb.repack implements proper table splitting.

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

- [otlLib] Put back the ``FONTTOOLS_GPOS_COMPACT_MODE`` environment variable to fix
regression in ufo2ft (and thus fontmake) introduced with v4.33.0 (2592, 2593).
This is deprecated and will be removed one ufo2ft gets updated to use the new
config setup.

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

- [OS/2 / merge] Automatically recalculate ``OS/2.xAvgCharWidth`` after merging
fonts with ``fontTools.merge`` (2591, 2538).
- [misc/config] Added ``fontTools.misc.configTools`` module, a generic configuration
system (2416, 2439).
Added ``fontTools.config`` module, a fontTools-specific configuration
system using ``configTools`` above.
Attached a ``Config`` object to ``TTFont``.
- [otlLib] Replaced environment variable for GPOS compression level with an
equivalent option using the new config system.
- [designspaceLib] Incremented format version to 5.0 (2436).
Added discrete axes, variable fonts, STAT information, either design- or
user-space location on instances.
Added ``fontTools.designspaceLib.split`` module to split a designspace
into sub-spaces that interpolate and that represent the variable fonts
listed in the document.
Made instance names optional and allow computing them from STAT data instead.
Added ``fontTools.designspaceLib.statNames`` module.
Allow instances to have the same location as a previously defined STAT label.
Deprecated some attributes:
``SourceDescriptor``: ``copyLib``, ``copyInfo``, ``copyGroups``, ``copyFeatures``.
``InstanceDescriptor``: ``kerning``, ``info``; ``glyphs``: use rules or sparse
sources.
For both, ``location``: use the more explicit designLocation.
Note: all are soft deprecations and existing code should keep working.
Updated documentation for Python methods and the XML format.
- [varLib] Added ``build_many`` to build several variable fonts from a single
designspace document (2436).
Added ``fontTools.varLib.stat`` module to build STAT tables from a designspace
document.
- [otBase] Try to use the Harfbuzz Repacker for packing GSUB/GPOS tables when
``uharfbuzz`` python bindings are available (2552). Disable it by setting the
"fontTools.ttLib.tables.otBase:USE_HARFBUZZ_REPACKER" config option to ``False``.
If the option is set explicitly to ``True`` but ``uharfbuzz`` can't be imported
or fails to serialize for any reasons, an error will be raised (ImportError or
uharfbuzz errors).
- [CFF/T2] Ensure that ``pen.closePath()`` gets called for CFF2 charstrings (2577).
Handle implicit CFF2 closePath within ``T2OutlineExtractor`` (2580).

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

- [otlLib] Disable GPOS7 optimization to work around bug in Apple CoreText.
Always force Chaining GPOS8 for now (2540).
- [glifLib] Added ``outputImpliedClosingLine=False`` parameter to ``Glyph.draw()``,
to control behaviour of ``PointToSegmentPen`` (6b4e2e7).
- [varLib.interpolatable] Check for wrong contour starting point (2571).
- [cffLib] Remove leftover ``GlobalState`` class and fix calls to ``TopDictIndex()``
(2569, 2570).
- [instancer] Clear ``AxisValueArray`` if it is empty after instantiating (2563).

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

- [varLib] fix instantiation of GPOS SinglePos values (2555).

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

- [subset] fix subsetting OT-SVG when glyph id attribute is on the root ``<svg>``
element (2553).