diff options
Diffstat (limited to 'Lib/fontTools/otlLib/builder.py')
| -rw-r--r-- | Lib/fontTools/otlLib/builder.py | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/Lib/fontTools/otlLib/builder.py b/Lib/fontTools/otlLib/builder.py index 7e144451..029aa3fc 100644 --- a/Lib/fontTools/otlLib/builder.py +++ b/Lib/fontTools/otlLib/builder.py @@ -2574,7 +2574,8 @@ class ClassDefBuilder(object): return self.classes_.add(glyphs) for glyph in glyphs: - assert glyph not in self.glyphs_ + if glyph in self.glyphs_: + raise OpenTypeLibError(f"Glyph {glyph} is already present in class.", None) self.glyphs_[glyph] = glyphs def classes(self): |