Merge pull request #2714 from fonttools/NotANone

[varLib.merge] fix NameError: 'NotANone'

Lib/fontTools/varLib/errors.py

@@ -120,6 +120,20 @@ class FoundANone(VarLibMergeError):
         return f"{stack[0]}=={cause['got']}\n"
 
 
+class NotANone(VarLibMergeError):
+    """one of the values in a list was not empty when it should have been"""
+
+    @property
+    def offender(self):
+        index = [x is not None for x in self.cause["got"]].index(True)
+        return index, self._master_name(index)
+
+    @property
+    def details(self):
+        cause, stack = self.cause, self.stack
+        return f"{stack[0]}=={cause['got']}\n"
+
+
 class MismatchedTypes(VarLibMergeError):
     """data had inconsistent types"""
 

Lib/fontTools/varLib/merger.py

@@ -31,6 +31,7 @@ from .errors import (
     ShouldBeConstant,
     FoundANone,
     MismatchedTypes,
+    NotANone,
     LengthsDiffer,
     KeysDiffer,
     InconsistentGlyphOrder,