branch: help misuse of hg branch to switch branches stable

branch: help misuse of hg branch to switch branches

Maybe beginners tend to use 'hg branch EXISTING_BRANCH' instead of
'hg update EXISTING_BRANCH' as me.
If so, let's help them to use 'update'.

Also removed '(use --force to override)' because it can mislead them.

--- a/mercurial/commands.py	Sat Mar 06 21:29:02 2010 -0800
+++ b/mercurial/commands.py	Tue Jan 12 22:49:10 2010 +0900
@@ -451,7 +451,7 @@
         if not opts.get('force') and utflabel in repo.branchtags():
             if label not in [p.branch() for p in repo.parents()]:
                 raise util.Abort(_('a branch of the same name already exists'
-                                   ' (use --force to override)'))
+                                   " (use 'hg update' to switch to it)"))
         repo.dirstate.setbranch(utflabel)
         ui.status(_('marked working directory as branch %s\n') % label)
     else:

--- a/tests/test-newbranch.out	Sat Mar 06 21:29:02 2010 -0800
+++ b/tests/test-newbranch.out	Tue Jan 12 22:49:10 2010 +0900
@@ -2,7 +2,7 @@
 foo
 marked working directory as branch bar
 % branch shadowing
-abort: a branch of the same name already exists (use --force to override)
+abort: a branch of the same name already exists (use 'hg update' to switch to it)
 marked working directory as branch default
 % there should be only one default branch head
 changeset:   3:bf1bc2f45e83