Bug#316337: Proof

[Goswin von Brederlow <brederlo@informatik.uni-tuebingen.de>]

roan.kattouw@home.nl writes:

> I ran strace -ff on an bzip2-error-spewing apt-get update, and came
> across one of the following traces (for a bzip2 subprocess):
>
> dup2(3, 0) = 0
> /* ... */
> execve("/usr/bin/bzip2", ["bzip2", "-d"], [/* 28 vars */]) = 0
> /* ... */
> read(0, "", 65536)                      = 0
> read(0, "", 65536)                      = 0
> write(2, "\nbzip2: Compressed file ends une"..., 97) = 97
> write(2, "bzip2: Function not implemented\n", 32) = 32
> write(2, "\tInput file = (stdin), output fi"..., 46) = 46
> write(2, "\nIt is possible that the compres"..., 240) = 240
> exit_group(2)                           = ?
>
> This proves that bzip2 is really fed an empty file. In the traces for
> one of the methods/ftp subprocesses I found:
>
> open("/var/lib/apt/lists/partial/ftp.debian.nl_debian_dists_stable_main_binary-i
> 386_Packages", O_RDONLY) = 3
> fcntl64(3, F_SETFD, FD_CLOEXEC) = 0
> pipe([4, 5]) = 0
> clone(child_stack=0, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, chil
> d_tidptr=0xb7cd4708) = 7029
>
> This proves that the empty file bzip2 is fed is really a
> /var/lib/apt/lists/partial/* file.

I think those are always "partial" files until they have been
verified. The placement might not mean it actualy is partial.

MfG
        Goswin