When looking through the code for understanding #2158, I stumbled upon some possibly undefined variable.
Let's take the following snippet:
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if isinstance(decode_parms, ArrayObject): |
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columns = 1 |
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bits_per_component = DEFAULT_BITS_PER_COMPONENT |
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for decode_parm in decode_parms: |
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if "/Columns" in decode_parm: |
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columns = decode_parm["/Columns"] |
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if LZW.BITS_PER_COMPONENT in decode_parm: |
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bits_per_component = decode_parm[LZW.BITS_PER_COMPONENT] |
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else: |
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columns = ( |
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1 if decode_parms is None else decode_parms.get(LZW.COLUMNS, 1) |
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) |
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colors = 1 if decode_parms is None else decode_parms.get(LZW.COLORS, 1) |
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bits_per_component = ( |
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decode_parms.get(LZW.BITS_PER_COMPONENT, DEFAULT_BITS_PER_COMPONENT) |
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if decode_parms |
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else DEFAULT_BITS_PER_COMPONENT |
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) |
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# PNG predictor can vary by row and so is the lead byte on each row |
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rowlength = ( |
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math.ceil(columns * colors * bits_per_component / 8) + 1 |
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) # number of bytes |
It seems like in the first branch (lines 144 to 150), colors will never be defined, thus possibly leading to a crash at line 164 if I did not miss something. (I do not have any PDF file for this, as I just stumbled upon this by accident.)