[morx] Minor

Lib/fontTools/ttLib/tables/otBase.py

@@ -233,6 +233,9 @@ class OTTableWriter(object):
 	def __getitem__(self, name):
 		return self.localState[name]
 
+	def __delitem__(self, name):
+		del self.localState[name]
+
 	# assembler interface
 
 	def getDataLength(self):

Lib/fontTools/ttLib/tables/otConverters.py

@@ -434,6 +434,7 @@ class StructWithLength(Struct):
 	def write(self, writer, font, tableDict, value, repeatIndex=None):
 		value.compile(writer, font)
 		writer['StructLength'].setValue(writer.getDataLength())
+		del writer['StructLength']
 
 
 class Table(Struct):