Comment 7 for bug 1472407

> ubuntu 12.04 + php 5.5.9 (from sources) => works
> ubuntu 14.04 + php 5.5.9 (from sources) => got error
> ubuntu 14.04 + php 5.5.10 (from sources) => works

This would imply that the fix is not in php itself, if 5.5.9 on 12.04 worked? Perhaps there is some interaction with an external library?

> In the server (ubuntu 14.04), I have the 5.5.9-1ubuntu4.11 version (the one
> with the problem) and then I compile php from sources (php 5.5.27) and
> linked with apache (2.4.7-1ubuntu4.4) and is working fine since then.

> I did the update and I instaled PHP 5.5.9-1ubuntu4.14 (cli) (built: Oct
> 28 2015 01:34:46), then linked with apache and try the form for upload
> a csv file, I got the problem again.

Looking at the upstream changelog for 5.5.10, there are only two mentioned changes to fileinfo: https://secure.php.net/ChangeLog-5.php#5.5.10.

bug #66731's fix was backported to 5.5.9+dfsg-1ubuntu2.
bug #66820's fix was backported to 5.5.9+dfsg-1ubuntu3.

I am going to verify that those backports are correct, but I feel like we do not have a root cause yet in this bug.