When doing "darcs push --dry-run" with "--set-default", I was expecting no
changes at all.  As it turns out, the 'set default' action *is* performed, in
other words, if a repository is given explicitly, this repository becomes the
default one.  This seems like a bug to me.  But tastes might differ...

Reproduction scenario, where /tmp/repo1 is the current defaultrepo (and where
there are no changes at all between the current repo, /tmp/repo1, and /tmp/repo2):

$ darcs push --dry-run
Pushing to "/tmp/repo1"...
No recorded local changes to push!
$ darcs push --dry-run --set-default /tmp/repo2
No recorded local changes to push!
$ darcs push --dry-run
Pushing to "/tmp/repo2"...
No recorded local changes to push!
$

Resolved in unstable with the following patch.  Thanks!

Tue Jul 17 12:16:07 CEST 2007  Eric Kow <eric.kow@loria.fr>
  * Do not set defaultrepo if --dry-run (issue186).