zdiff show no difference when comparing two gzipped files

[Jörg-Volker Peetz]

Package: gzip
Version: 1.3.12

When I invoke zdiff with two names of gzipped files whose contents are
different, no difference is shown.
For example:

$ echo line1 > x
$ cp x y
$ echo line2 >> y
$ gzip x y
$ zdiff x.gz y.gz

To correct this line 107 of zdiff should be changed to

       eval "$cmp" /dev/fd/5 - >&3) 5<&0

i.e., ">&3" has to be filled in.

I am using Debina GNU/Linux testing with a self compiled stock kernel
2.6.21.6 and libc6 2.6.
I have sent this bug report also to the Debian maintainers.
-- 
Regards,
Jörg-Volker.