[patch] Fix fortran/25031, multiple allocations

[Paul Thomas]

Thomas,

>I found it quite interesting (especially because I am currently trying
>to learn walking with TREEs).   I have also incorporated your change.
>  
>
I knew that you would find it amusing!  The change tidies up the patch 
somewhat.

Before you tackle the other business of allocations with negative 
lengths, give me 48 hours to get my attempt at this out of the door.  I 
am a bit overwhelmed at work and have promised to review Roger's 
patch(es!) on depedency checking.

Thanks for the patch.

Paul