"gunzip --list" displays nonsense for very large files

[rivode]

Binary package hint: gzip

"gunzip --list" gives incorrect results for files of size (2^32 - 1) bytes or larger.

To reproduce:

$ dd if=/dev/zero bs=1 seek=$((2**32-2)) count=1 of=noerror
$ dd if=/dev/zero bs=1 seek=$((2**32-1)) count=1 of=error
$ gzip -c noerror > noerror.gz
$ gzip -c error > error.gz
$ gunzip --list noerror.gz
         compressed uncompressed ratio uncompressed_name
            4168183 4294967295 99.9% noerror
$ gunzip --list error.gz
         compressed uncompressed ratio uncompressed_name
            4168181 0 0.0% error

I'm using gzip 1.3.12-8ubuntu1 on Karmic.

[P.Constantine (pconstantine)]

Same thing on Solaris, and all other Linux flavors I've tried.
Seems like ancient gunzip bug that nobody wants to fix.

[rivode (bugs-launchpad-net-rivode)]

It turns out it's a problem with the file format:

http://lists.gnu.org/archive/html/bug-gzip/2010-03/msg00009.html