Re: Intermittent failures retrieving process exit codes

[Lasse Collin <lasse.collin@tukaani.org>]

On 2013-11-15 Denis Excoffier wrote:
> Very briefly, my problem is that when i "tar xf
> —use-compress-program=xz", i get:
> tar: Unexpected EOF in archive
> tar: Unexpected EOF in archive
> tar: Error is not recoverable: exiting now
> and the last file of the archive is truncated at some 512bytes block.
> This occurs on Windows 7 (not on XP); with xz-5.1.3alpha (not with
> xz-5.1.2alpha or xz-5.0.5); never on most tar.xz files; almost always
> on some (rare) tar.xz files (one notable example is
> bc-1.06.95.tar.bz2 bunzip2’ed and then xz’ed); depends on the .tar
> file itself, not on the option (like -9e, -0) used to create
> the .tar.xz; never with "tar tf"; and with all tar’s i have tested.
> The return code of all the involved xz -d commands is always zero
> though. Perhaps after all, this is unrelated?

xz 5.1.3alpha has some new file I/O code that uses non-blocking file
descriptors, the self-pipe trick, and poll(). It's there to fix a race
condition in signal handling. Since you say it works with 5.1.2alpha, I
wonder could there be a bug with the new I/O code in xz or if the code
in xz triggers a bug in Cygwin or Windows.

If you haven't already tried, please compile both 5.1.2alpha and
5.1.3alpha from source while keeping everything else unchanged, and see
if the bug really only occurs with 5.1.3alpha.

-- 
Lasse Collin  |  IRC: Larhzu @ IRCnet & Freenode

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