View masters, even if master count is not the same...

[HansG1]

Changing the code from line 42 to the following would make it possible to view the according masters of another font, even if it has more masters than the current:

if len(masters) != len(nextFontMasters):
   if activeMasterIndex <= len(nextFontMasters):
      nextLayer = nextGlyph.layers[activeMasterIndex]
   else:
      nextLayer = nextGlyph.layers[0]
else:
   nextLayer = nextGlyph.layers[activeMasterIndex]