bug#23315: Bug in gzip-1.7

[Mark Adler]

On Apr 19, 2016, at 1:34 PM, Jim Meyering <address@hidden> wrote:
> Note however that you really should not rely on gzip's -l option, due
> to the format-imposed limit an input of size 4TiB or larger, the size
> reported by --list (-l) will be reduced modulo 2^32, i.e., "wrong".

A side note that "pigz -lt" will always report the correct length since it 
decompresses.

Another side note is that gzip -l assumes not only that the input was less than 
2^32 bytes, but also that the last gzip entry is also the first gzip entry, and 
that there is no extraneous junk at the end of the gzip file. You can spoof 
gzip -l simply by concatenating two short gzip files, or by adding one or more 
bytes to the end of the gzip file.

Mark