shadowfacts/fonttools
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

[subset] Fix chaos handling to be more inclusive

Browse Source 
If a contextual lookup recurses twice on the same index, that index
most be marked chaotic for the second recursion.

Also, when a non-1-to-1 recursion happens, only mark glyph locations
after current to be chaotic, not everything.

I believe this fixes a bug that before we were not inclusive enough.
Now we might have introduced more false positives, but we are at least
correct.
This commit is contained in:
Behdad Esfahbod 2015-04-01 18:39:25 -07:00
parent 2a7007df7b
commit 24264cb7f8
1 changed files with 18 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

30
Lib/fontTools/subset.py
View File

@ -854,12 +854,12 @@ def closure_glyphs(self, s, cur_glyphs):
if not all(all(c.Intersect(s.glyphs, cd, k) for k in klist) if not all(all(c.Intersect(s.glyphs, cd, k) for k in klist)
for cd,klist in zip(ContextData, c.RuleData(r))): for cd,klist in zip(ContextData, c.RuleData(r))):
continue continue
chaos = False chaos = set()
for ll in getattr(r, c.LookupRecord): for ll in getattr(r, c.LookupRecord):
if not ll: continue if not ll: continue
seqi = ll.SequenceIndex seqi = ll.SequenceIndex
# XXX Go into chaos mode upon duplicate seqi if seqi in chaos:
if chaos: # TODO Can we improve this?
pos_glyphs = None pos_glyphs = None
else: else:
if seqi == 0: if seqi == 0:
@ -867,7 +867,9 @@ def closure_glyphs(self, s, cur_glyphs):
else: else:
pos_glyphs = frozenset([r.Input[seqi - 1]]) pos_glyphs = frozenset([r.Input[seqi - 1]])
lookup = s.table.LookupList.Lookup[ll.LookupListIndex] lookup = s.table.LookupList.Lookup[ll.LookupListIndex]
chaos = chaos or lookup.may_have_non_1to1() chaos.add(seqi)
if lookup.may_have_non_1to1():
chaos.update(range(seqi, len(r.Input)+2))
recursions.add((lookup, pos_glyphs)) recursions.add((lookup, pos_glyphs))
elif self.Format == 2: elif self.Format == 2:
ClassDef = getattr(self, c.ClassDef) ClassDef = getattr(self, c.ClassDef)
@ -882,12 +884,12 @@ def closure_glyphs(self, s, cur_glyphs):
if not all(all(c.Intersect(s.glyphs, cd, k) for k in klist) if not all(all(c.Intersect(s.glyphs, cd, k) for k in klist)
for cd,klist in zip(ContextData, c.RuleData(r))): for cd,klist in zip(ContextData, c.RuleData(r))):
continue continue
chaos = False chaos = set()
for ll in getattr(r, c.LookupRecord): for ll in getattr(r, c.LookupRecord):
if not ll: continue if not ll: continue
seqi = ll.SequenceIndex seqi = ll.SequenceIndex
# XXX Go into chaos mode upon duplicate seqi if seqi in chaos:
if chaos: # TODO Can we improve this?
pos_glyphs = None pos_glyphs = None
else: else:
if seqi == 0: if seqi == 0:
@ -895,19 +897,21 @@ def closure_glyphs(self, s, cur_glyphs):
else: else:
pos_glyphs = frozenset(ClassDef.intersect_class(s.glyphs, getattr(r, c.Input)[seqi - 1])) pos_glyphs = frozenset(ClassDef.intersect_class(s.glyphs, getattr(r, c.Input)[seqi - 1]))
lookup = s.table.LookupList.Lookup[ll.LookupListIndex] lookup = s.table.LookupList.Lookup[ll.LookupListIndex]
chaos = chaos or lookup.may_have_non_1to1() chaos.add(seqi)
if lookup.may_have_non_1to1():
chaos.update(range(seqi, len(getattr(r, c.Input))+2))
recursions.add((lookup, pos_glyphs)) recursions.add((lookup, pos_glyphs))
elif self.Format == 3: elif self.Format == 3:
cur_glyphs = frozenset(cur_glyphs) cur_glyphs = frozenset(cur_glyphs)
if not all(x.intersect(s.glyphs) for x in c.RuleData(self)): if not all(x.intersect(s.glyphs) for x in c.RuleData(self)):
return [] return []
r = self r = self
chaos = False chaos = set()
for ll in getattr(r, c.LookupRecord): for ll in getattr(r, c.LookupRecord):
if not ll: continue if not ll: continue
seqi = ll.SequenceIndex seqi = ll.SequenceIndex
# XXX Go into chaos mode upon duplicate seqi if seqi in chaos:
if chaos: # TODO Can we improve this?
pos_glyphs = None pos_glyphs = None
else: else:
if seqi == 0: if seqi == 0:
@ -915,7 +919,9 @@ def closure_glyphs(self, s, cur_glyphs):
else: else:
pos_glyphs = frozenset(r.InputCoverage[seqi].intersect_glyphs(s.glyphs)) pos_glyphs = frozenset(r.InputCoverage[seqi].intersect_glyphs(s.glyphs))
lookup = s.table.LookupList.Lookup[ll.LookupListIndex] lookup = s.table.LookupList.Lookup[ll.LookupListIndex]
chaos = chaos or lookup.may_have_non_1to1() chaos.add(seqi)
if lookup.may_have_non_1to1():
chaos.update(range(seqi, len(r.InputCoverage)+1))
recursions.add((lookup, pos_glyphs)) recursions.add((lookup, pos_glyphs))
else: else:
assert 0, "unknown format: %s" % self.Format assert 0, "unknown format: %s" % self.Format