For several years, I've been using amanda to make backups, with gzip to
compress them.

Recently, it stopped working.  Apparently, gzip will error out rather than
indicate that the source data is greater than 4GB.

This is new behavior, and it is very unpleasant behavior, because there
doesn't seem to be any way to override it, let alone a way to make it be
overridden automatically by amanda.

I assume this is a workaround for the problem of gzip -t failing on such
archives, but I don't think that helps much.

It looks as though "maybe_warn" in gzip.c has the side-effect of setting exit
status to zero.  Perhaps the thing to do would be to save exit status before
calling it, and restore it afterwards, to keep amanda from seeing this as
a fatal error?

-s