Comment 3 for bug 52613

And there being no master bug report is good because someone can resolve a bug report by e-mail and it will Do The Right Thing, even if in the meantime someone else discovered that the bug had previously been reported and marked it as such. Is that right, and are there any other reasons?

Please also explain the "Before bugs can be merged they must be in exactly the same state, either all open or all closed" part. Is that solely to make merging commutative? In my experience it's common for duplicates to be reported where the original is resolved fixed, because a version with the fix has not yet been released.