Subversion changeset sync doesn't handle copy + edit

[cboos]

i.e. the following sequence of operations:

$ svn cp a b
$ vim b
$ svn ci -m "copied a to b, then edited b"

is reported as a pure copy, with no links to the diffs between a and b.

See also ​[h774] for an example: in the changeset view,
there are no diffs shown for mailto.py even though there are
​diffs.

I'm pretty sure it used to work, we need to add a test case for this.

[cboos]

Another symptom of this problem here: [3342/trunk/trac/util]

[cboos]

Fixed by r3387.