[Python-apps-team] Bug#701350: s3ql: ftbfs with GCC-4.8

[Nikolaus Rath]

retitle 701350 Data corruption with eglibc 2.17
thanks

The unit test in question fails when using eglibc 2.17, independent of
the gcc version.

The reason is a bug in src/s3ql/_deltadump.pyx, which repositions a file
descriptor associated with a FILE* stream without first calling
fflush(). I do not understand why this problem does not show up when
using eglibc 2.13.

I think relying on this to work is not a good idea, because if it ever
becomes a problem (without a rebuild of S3QL), s3ql will suddenly store
malformed metadata that cannot be loaded again. The problem is made
worse because this affects only the metadata uploaded to the remote
server, but not the locally cached copy. So unless the user explicitly
tests reloading the metadata from the server, the corruption will not
show up until it's too late.

I'm not sure if I should bump the severity to grave (even though it
looks as if it should cause data loss, things seem to work as long as
eglibc 2.13 is used), but I'll try to get the necessary patch into wheezy.


Best,

   -Nikolaus

-- 
 »Time flies like an arrow, fruit flies like a Banana.«

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