[instancer] Add assert

2022-08-08 11:06:32 -06:00 · 2022-08-08 11:06:32 -06:00 · f6ce737476
commit f6ce737476
parent c3fa1b59ac
1 changed files with 4 additions and 0 deletions
--- a/Lib/fontTools/varLib/instancer/init.py
+++ b/Lib/fontTools/varLib/instancer/init.py
@ -251,6 +251,10 @@ def changeTupleVariationAxisLimit(var, axisTag, axisLimit):
        if tent is None:
            newVar.axes.pop(axisTag)
        else:
+            # Sometimes happens when can't be solved. Eg. if a dirac function
+            # (tent with upper==peak==lower) is placed at axisLimit's default
+            # location.
+            assert tent[1] != 0, tent
            newVar.axes[axisTag] = tent
        if scalar != 1:
            newVar.scaleDeltas(scalar)