When reporting [this question on SF](http://serverfault.com/questions/272337/i-am-using-a-memory-engine-but-mysql-still-writes-to-my-disk/272352#272352) as an exact duplicate of [this one over on DBA](http://dba.stackexchange.com/questions/2868/i-am-using-a-memory-engine-but-mysql-still-writes-to-my-disk-why), the description of question 2868 on SF is pulled through, not the description of question 2868 on dba.se.

The comment that gets added was (before I applied an edit):

    possible duplicate of [What is the best open-source email solution package](http://serverfault.com/questions/2868/what-is-the-best-open-source-email-solution-package)
rather than 

    possible duplicate of [I am using a MEMORY engine but MYSQL still writes to my disk…why?](http://dba.stackexchange.com/questions/2868/i-am-using-a-memory-engine-but-mysql-still-writes-to-my-disk-why)
which I expected.

Is this behavior-as-intended (i.e. the feature is intended for marking duplicates within one site, and cross-posted duplicates should be reported some other way) or a bug?

As a side question: would it be worth implementing a distinction between questions from different users that carry the same meaning (which just want to be closed with a link to the older question) and cross-posts (in which case merging the answers, before closing the copies on all but the most relevant site, makes more sense)?