Hi,
I want to report a flaw in the gzip program when using option -l
Version:
Gzip for Windows as available from
http://gnuwin32.sourceforge.net/packages/gzip.htm
Version 1.3.12, 32 bit.
Symptom:
"gzip -l" reports wrong original size and possibly negative compression
ratio when original size is bigger than 4GByte.
Reproduce:
1. Create a file that is bigger than 4 GB, for example the file
"gziptest" with size 4,394,364,468 bytes.
2. Compress this file using gzip, in this example by "gzip gziptest"
3. against the compressed version, run "gzip -l", in this example "gzip
-l gziptest.gz"
==> gzip reports a wrong original size and possibly a negative compression
rate, similar to this:
C:\temp>gzip -l gziptest.gz
compressed uncompressed ratio uncompressed_name
384204661 99397172 -286.5% gziptest
In other words, an unsigned long 32 bit integer is used for the
computation which has an unhandled overflow.
Thus, the hex value 100000000x == 4,294,967,296 is accidentally subtracted
from the correct original length.
If someone provides a fix for this, please let me know.
Best regards,
Andreas
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Dr. Andreas Arning
Master Inventor
WebSphere Business Process Solutions - Business Process Choreographer
BPM Samples - http://publib.boulder.ibm.com/bpcsamp/index.html
Phone: +49-7031-16-2359
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