archive/zip: crash opening zip file with corrupt extras defined

[dustin]

I've got some code that stores timestamps in an extras header in a zip.  As of some
post-1.0.3 version, one of my tests started failing.  I've got it narrowed down to
approximately the following:

http://play.golang.org/p/kfigcf76RE

If you comment out the Extras in the header, the test passes fine.

[davecheney]

Comment 1:

I believe the problem is the Extra data needs to include its own tag and len headers.
While I cannot find a tag for nano time headers, I can at fix zip.Reader to avoid
panicing when reading a corrupt Extra header.

Labels changed: added priority-later, removed priority-triage.

Owner changed to @davecheney.

Status changed to Started.

[dustin]

Comment 2:

Thanks for the education on this, too.  Supplying the right input at the time I'm
writing the zipfile (and reading it back out properly) makes my app happy again.
It may be good to build a reader/writer utility for extras.  I ended up with something
that looks a little too much like the reader code.

[davecheney]

Comment 3:

This issue was closed by revision 640d818.

Status changed to Fixed.