Re: jka-compr.el doesn't recognise gzipped files from their magic bytes

[Stephen J. Turnbull]

Eli Zaretskii writes:

 > It would be a performance hit: Emacs will need to open a file and read
 > its first bytes just to know what to do with it.

This is precisely what an autodetecting coding system does.  You've
already got that code, why not use it? ;-)

According to some ancient notes from Ben Wing this could be a little
tricky for gzip, but I can't imagine it's actually *hard*.