maildir-size-fix.pl - The file command can wrongly detect gzipped mails as being Minix filesystems

[Rarylson Freitas]

Hi,

Some days ago, I have used the maildir-size-fix.pl script (cited in this
mail thread: http://www.dovecot.org/list/dovecot/2013-January/087942.html,
in available here:
http://dovecot.org/tools/maildir-size-fix.pl).

This is a very good script and helped me a lot!

However, some compressed mails where misdetected as non-compressed mail. So
I discovered that some versions of the file command (some old versions) can
wrongly detect gzipped files as being Minix filesystems.

Actually, the error was occurring in about 1 gzipped mail for each 60000 or
100000 mails.

I reported this file command bug here:
https://bugs.launchpad.net/ubuntu/+source/file/+bug/1646233.

But I think it's worth to make a small improvement in maildir-size-fix.pl,
making it more error prone. What do you, guys, think about this?

This is the patch I'm proposing:

```
--- maildir-size-fix.pl.orig    2016-12-01 14:41:30.044689101 -0200
+++ maildir-size-fix.pl    2016-12-01 14:49:42.971197715 -0200
@@ -37,7 +37,10 @@

     return $stat[7];
   }
-  my $type=`file "$path"`;
+  # Detecting all possible types (keep going) since some versions of the
file
+  # command can wrong detect gzip files as Minix filesystems.
+  # See: https://bugs.launchpad.net/ubuntu/+source/file/+bug/1646233
+  my $type=`file -k "$path"`;
   my $program = "";
   if ($type =~ /gzip/) {
     $program = "gunzip";

```

--
*Rarylson Freitas*