When lazy-loading tables, copy ValueFormat

Otherwise it may be overwritten before we use it.

Lib/fontTools/ttLib/tables/otBase.py

@@ -98,16 +98,19 @@ class OTTableReader:
 		self.valueFormat = valueFormat
 		self.cachingStats = cachingStats
 	
-	def getSubReader(self, offset):
+	def getSubReader(self, offset, persistent=False):
 		offset = self.offset + offset
 		if self.cachingStats is not None:
 			try:
 				self.cachingStats[offset] = self.cachingStats[offset] + 1
 			except KeyError:
 				self.cachingStats[offset] = 1
-		
+		valueFormat = self.valueFormat
+		if persistent:
+			valueFormat = tuple(ValueRecordFactory(v) for v in valueFormat)
+
 		subReader = self.__class__(self.data, self.tableType, offset,
-			self.valueFormat, self.cachingStats)
+			valueFormat, self.cachingStats)
 		return subReader
 	
 	def readUShort(self):
@@ -743,6 +746,9 @@ valueRecordFormatDict = _buildDict()
 class ValueRecordFactory:
 	
 	"""Given a format code, this object convert ValueRecords."""
+
+	def __init__(self, other=None):
+		self.format = other.format if other else None
 	
 	def setFormat(self, valueFormat):
 		format = []

Lib/fontTools/ttLib/tables/otConverters.py

@@ -159,7 +159,9 @@ class Struct(BaseConverter):
 
 class Table(Struct):
 	
-	def read(self, reader, font, tableStack):
+	def read(self, reader, font, tableStack, lazy=True):
+		# For now, we lazy-decompile all tables.  Perhaps we should
+		# use a more sophisticated heuristic here.
 		offset = reader.readUShort()
 		if offset == 0:
 			return None
@@ -168,11 +170,9 @@ class Table(Struct):
 			print "*** Warning: offset is not 0, yet suspiciously low (%s). table: %s" \
 					% (offset, self.tableClass.__name__)
 			return None
-		subReader = reader.getSubReader(offset)
+		subReader = reader.getSubReader(offset, persistent=lazy)
 		table = self.tableClass()
-		# For now, we lazy-decompile all tables.  Perhaps we should
-		# use a more sophisticated heuristic here.
-		if True:
+		if lazy:
 			# Lazy decompile
 			table.reader = subReader
 			table.font = font