* [subset CFF] Fix bug in de-subroutinizing when subroutines contain hints, issue 1493
The code was skipping executing a subroutine if it had already been desubroutinized. The initial set of vstemhm and hstemhm operators and values may be in a subroutine. If a charstring is being executed which calls such subroutines, they still need to be executed in order to count the number of hint values seen, so that the byte length of the hintmask can be calculated.
I fixed this bug by executing subroutines even if they have already been desubroutinized, as long as (we don't know yet if we are doing hintmasks) or ( we do need a hintmask, but have not yet seen it).
Clean up code per Cosimo's suggestions:
In arg list for stop_hint_count(), use *args to accept unused argument, rather than a dummy positional argument.
Change stop_hintcount_ops to a from a global variable to a class variable in _DesubroutinizingT2Decompiler.
Remove un-needed 'return' at line 387
Remove duplicate assignment of cs at line 437
Add patch for the bug where AttributeError is encountered when remove_hints is run after desubroutinize: remove lines deleting the GlobalSubrs for each FontDict. This always needed to be done only once, and is now in any case done in cff.GlobalSubrs.clear(), at the end of the desubroutinize() function.
Changed test case subset_test.py::'test_no_hinting_desubroutinize_CFF' to reference a font with a non-empty GlobalSubr, in order to trigger AttributeError traceback.
so that's comparable/hashable/immutable and can be used as key in a dict or set.
The fromXML instance method was dropped since it relied on the object being mutable.
A fromHex classmethod replaces it.
Fixes#1483
'remove_unused_subroutines' method expects a 'GlobalSubrs' attribute but the 'desubroutinize'
method deletes it. We don't have to call 'remove_unused_subroutines' at the end of 'desubroutinize'
method, we can just delete all the local subroutines, and clear the GlobalSubrsIndex.
Only call 'remove_unused_subroutines' method once, when we are not desubroutinizing.
The dunder method doesn't seem to be doing anything other than providing
an `in_cff2` attribute. Do that with a property instead of bending
__getattr__.
This one confused me when I was working on
https://github.com/fonttools/fonttools/pull/1488.
We need to raise AttributeError for non-existing dunder methods like
'__deepcopy__' or '__getstate__', because deepcopy() and pickle.load()
test for these on the instance using getattr() and treat the resulting
AttributeError as a signal that the object doesn't implement these custom
hooks. If we don't do that, we enter an infinite recursion as we attempt
to look up the missing dunder methods in the 'rawDict' dictionary,
because 'rawDict' is set inside __init__, but __init__ is not invoked
while unpickling (only __new__ is); thus self.rawDict is also missing
and __getattr__ is invoked with argument 'rawDict' again and again until
it crashes with RecursionError. Phew.
Fixes https://github.com/fonttools/fonttools/pull/1488
* Revert "load_masters: actually assign font attributes"
This reverts commit ef1d4cd02d1e46f5dac3914f547a6e4275cf3077, which caused a
crash in `interpolate_layout()` when `deepcopy`ing OTFs.
Amend code and tests while I work on a real fix.
