This was reported by a client, I haven't reproduced it. Checking the relevant
code, it's both in 5.2 and 6.0.
Quoting from the ticket:
The production and training systems have both seen circumstances where the link
to a document from search results and the content-center link on various cms
pages point to an incorrect url.
The problem occurs in com.arsdigita.kernel.SiteNode.getRootSiteNode() and may be
related to these comments in that method:
// cache the site node statically
// note lack of synchronization. worst case:
// two different threads concurrently query for the root
// site node and one gets garbage collected. BFD.
The url fragment returned should be an empty string but is instead the string
"null". Once this is cached incorrectly, it persists on the site for an
indefinite amount of time.
I'm the client being referred to. The version we're getting this on
is 5.1. Sadly, we're not up to 5.2 yet. Also, the bug is sporadic
(appears to be a timing issue) so providing a reproducible test case