[wonderercat]

Once again you're demonstrating that you really don't know how to use Mercurial, but feel the need to bash its usability anyway.

   hg update <branchname>

will do exactly what you want. It's even the same command as in SVN.

[guard-of-terra]

I change a file.

do

hg update default

get:

abort: crosses branches (merge branches or use --clean to discard changes)

So?