[>64k:layout] Add GSUB/GPOS version 2.0

To fix offset overflows of LookupList itself.

Implements harfbuzz/boring-expansion-spec#58

Lib/fontTools/merge/layout.py

@@ -422,6 +422,6 @@ def layoutPostMerge(font):
 
 				beyond64k = len(font.getGlyphOrder()) > 65535
 				if beyond64k:
-					t.table.LookupList.upgrade64k(font.getReverseGlyphMap())
+					t.table.upgrade64k(font.getReverseGlyphMap())
 
 		# TODO FeatureParams nameIDs

Lib/fontTools/merge/upgrade64k.py

@@ -95,9 +95,17 @@ def upgrade64k(self, reverseGlyphMap):
 		if not st: continue
 		st.upgrade64k(reverseGlyphMap)
 
-@add_method(otTables.LookupList)
+@add_method(otTables.LookupList32)
 def upgrade64k(self, reverseGlyphMap):
 	for l in self.Lookup:
 		if not l: continue
 		l.upgrade64k(reverseGlyphMap)
 
+@add_method(otTables.GSUB,
+		otTables.GPOS)
+def upgrade64k(self, reverseGlyphMap):
+	if self.Version < 0x00020000:
+		self.LookupList32 = otTables.LookupList32()
+		self.LookupList32.Lookup = self.LookupList.Lookup
+		self.Version = 0x00020000
+	self.LookupList32.upgrade64k(reverseGlyphMap)

Lib/fontTools/ttLib/tables/otBase.py

@@ -743,11 +743,11 @@ def getOverflowErrorRecord(self, item):
 			else: # who knows how far below the SubTable level we are! Climb back up to the nearest subtable.
 				itemName = ".".join([self.name, itemName])
 				p1 = self.parent
-				while p1 and p1.name not in ['ExtSubTable', 'SubTable']:
-					itemName = ".".join([p1.name, itemName])
+				while p1 and getattr(p1, 'name', None) not in ['ExtSubTable', 'SubTable']:
+					itemName = ".".join([getattr(p1, 'name', '<none>'), itemName])
 					p1 = p1.parent
 				if p1:
-					if p1.name == 'ExtSubTable':
+					if getattr(p1, 'name', None) == 'ExtSubTable':
 						LookupListIndex = p1.parent.parent.repeatIndex
 						SubTableIndex = p1.parent.repeatIndex
 					else:

Lib/fontTools/ttLib/tables/otConverters.py

@@ -481,11 +481,9 @@ class Version(SimpleValue):
 	staticSize = 4
 	def read(self, reader, font, tableDict):
 		value = reader.readLong()
-		assert (value >> 16) == 1, "Unsupported version 0x%08x" % value
 		return value
 	def write(self, writer, font, tableDict, value, repeatIndex=None):
 		value = fi2ve(value)
-		assert (value >> 16) == 1, "Unsupported version 0x%08x" % value
 		writer.writeLong(value)
 	@staticmethod
 	def fromString(value):

Lib/fontTools/ttLib/tables/otData.py

@@ -82,6 +82,11 @@
 		('Offset', 'Lookup', 'LookupCount', 0, 'Array of offsets to Lookup tables-from beginning of LookupList -zero based (first lookup is Lookup index = 0)'),
 	]),
 
+	('LookupList32', [
+		('uint16', 'LookupCount', None, None, 'Number of lookups in this table'),
+		('Offset32', 'Lookup', 'LookupCount', 0, 'Array of offsets to Lookup tables-from beginning of LookupList -zero based (first lookup is Lookup index = 0)'),
+	]),
+
 	('Lookup', [
 		('uint16', 'LookupType', None, None, 'Different enumerations for GSUB and GPOS'),
 		('LookupFlag', 'LookupFlag', None, None, 'Lookup qualifiers'),
@@ -180,7 +185,8 @@
 		('Version', 'Version', None, None, 'Version of the GPOS table- 0x00010000 or 0x00010001'),
 		('Offset', 'ScriptList', None, None, 'Offset to ScriptList table-from beginning of GPOS table'),
 		('Offset', 'FeatureList', None, None, 'Offset to FeatureList table-from beginning of GPOS table'),
-		('Offset', 'LookupList', None, None, 'Offset to LookupList table-from beginning of GPOS table'),
+		('Offset', 'LookupList', None, 'Version < 0x00020000', 'Offset to LookupList table-from beginning of GPOS table'),
+		('Offset32', 'LookupList32', None, 'Version >= 0x00020000', 'Offset to LookupList table-from beginning of GPOS table'),
 		('LOffset', 'FeatureVariations', None, 'Version >= 0x00010001', 'Offset to FeatureVariations table-from beginning of GPOS table'),
 	]),
 
@@ -620,7 +626,8 @@
 		('Version', 'Version', None, None, 'Version of the GSUB table- 0x00010000 or 0x00010001'),
 		('Offset', 'ScriptList', None, None, 'Offset to ScriptList table-from beginning of GSUB table'),
 		('Offset', 'FeatureList', None, None, 'Offset to FeatureList table-from beginning of GSUB table'),
-		('Offset', 'LookupList', None, None, 'Offset to LookupList table-from beginning of GSUB table'),
+		('Offset', 'LookupList', None, 'Version < 0x00020000', 'Offset to LookupList table-from beginning of GSUB table'),
+		('Offset32', 'LookupList32', None, 'Version >= 0x00020000', 'Offset to LookupList table-from beginning of GSUB table'),
 		('LOffset', 'FeatureVariations', None, 'Version >= 0x00010001', 'Offset to FeatureVariations table-from beginning of GSUB table'),
 	]),