Bug#624122: Hash Sum mismatch

[Johannes Stezenbach <js@sig21.net>]

I'm also seeing the Hash Sum mismatch often since about a week ago,
maybe since "[UPGRADE] apt:amd64 0.9.16 -> 0.9.16.1" (sid) but I did not
downgrade to confirm.  However, it seems the issue is caused
by xz decompressor truncating the files.  For example:

# ls -l /var/lib/apt/lists/partial/
-rw-r--r-- 1 root root  7067192 Mar 21 15:05 ftp.de.debian.org_debian_dists_unstable_main_source_Sources
-rw-rw-rw- 1 root root 11841536 Mar 21 15:05 ftp.de.debian.org_debian_dists_unstable_main_source_Sources.decomp.FAILED
# xzcat ftp.de.debian.org_debian_dists_unstable_main_source_Sources > ftp.de.debian.org_debian_dists_unstable_main_source_Sources.d
# ls -l ftp.de.debian.org_debian_dists_unstable_main_source_Sources.d
-rw-r--r-- 1 root root 32434409 Mar 21 20:34 ftp.de.debian.org_debian_dists_unstable_main_source_Sources.d
# sha1sum *
6701076d9d340be45b39be5ac212d69b3e3db34b  ftp.de.debian.org_debian_dists_unstable_main_source_Sources
50eec7dd53aa1b6b45f360a67418f0253c5e99ec  ftp.de.debian.org_debian_dists_unstable_main_source_Sources.d
a0d54d0ed700a9ec8a27b47f45b3bff18c2177b9  ftp.de.debian.org_debian_dists_unstable_main_source_Sources.decomp.FAILED

# grep 6701076d9d340be45b39be5ac212d69b3e3db34b ../ftp.de.debian.org_debian_dists_unstable_InRelease
 6701076d9d340be45b39be5ac212d69b3e3db34b  7067192 main/source/Sources.xz
# grep 50eec7dd53aa1b6b45f360a67418f0253c5e99ec ../ftp.de.debian.org_debian_dists_unstable_InRelease
 50eec7dd53aa1b6b45f360a67418f0253c5e99ec 32434409 main/source/Sources

And diffing the two decompressed files shows the .decomp.FAILED
is just truncated.

FWIW, I do not have APT::Get::List-Cleanup "false" but I do
have Acquire::PDiffs "false".

HTH,
Johannes