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Hello,

I have done some additional testing to the LZW filter and found 2
problems. I extracted a LZW stream of a PDF
(http://www.kripsy.de/texte/sp/rs_sit_kripsy.pdf) with

$ pdfshow -e -b  rs_sit_kripsy.pdf 3 > lzwstream

Decoding this with pdf-filter outputs a different result as with pdfshow
(MuPDF). (the first 400 byte are equal but pdfshow is right as it shows
the full text)

pdf-filter call:
$ ./pdf-filter -i lzwstream -o lzwdecoded --lzwdec --lzw-earlychange

pdfshow decode call:
$ pdfshow rs_sit_kripsy.pdf 3

Attached you find the lzwstream for input and both outputs.


If I call ./pdf-filter without --lzw-earlychange I get a Segmentation fault

Program received signal SIGSEGV, Segmentation fault.
0x00007ffff7b73f2b in lzw_dict_decode (d=0x60fb68, code=411,
decode=0x60faf8, size=0x60fb00) at base/pdf-stm-f-lzw.c:325
325           *(*decode)-- = d->table[code].suffix;

I think the problem is that the code can not be found in the table
because of the missing earlychange parameter. (Of course an error
message would be better).

Regards,
Georg
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Attachment: lzw-filter-bug.tar.gz
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