Joomla! 1.0.13 Admin session dies for certain $task values

Description:
Clicking toolbar buttons in the backend other than ‘save‘ or ‘apply‘ results in being logged out when using Joomla!

Reported on:
1.0.13

Affected functions:
initSessionAdmin()

Related files:
includes/joomla.php

Well,
VirtueMart is also affected by this bug.
The problem is indeed a wrong order of the calls to initSessionAdmin and doGzip at the end of the file /administrator/index2.php.

If we change:

103      doGzip();
104      
105      // if task action is ’save’ or ‘apply’ redo session check
106      if ( $task == ’save’ || $task == ‘apply’ ) {
107         $mainframe->initSessionAdmin( $option, ” );
108      }

to

102      // if task action is ’save’ or ‘apply’ redo session check
103      if ( $task == ’save’ || $task == ‘apply’ ) {
104         $mainframe->initSessionAdmin( $option, ” );
105      }
106      doGzip();

the problem is gone.