[Zope-CMF] Patch to make viewing portal instance quit Zope :-(

[Shane Hathaway]

Chris Withers wrote:
> The attached patch is supposed to enable the paths specified in skin layers
> to be of the form /folder/something/else rather than forcing them to be
> contained within the skins tool.
> 
> However, all it succeeds in doing is causing Zope to GPF some time after
> getSkinByPath returns.

1) The skins tool deliberately unlinks itself temporarily from the
acquisition chain to avoid the need to play with security.  
Anything inside portal_skins is considered free game but skin paths
can't leave the sandbox.

2) This code is executed before authentication occurs.  I'm not sure but
I think restrictedTraverse() will work, it's just that privileged skins
won't work.

3) The original code carefully avoids throwing exceptions and performing
recursive lookups.  Your current code starts fires. :-)

Shane