mq: let the user choose where .orig files are kept

This patch uses cmdutil.origpath to let the user decide where .orig files are
kept when backup files are created.

hgext/mq.py

@@ -697,11 +697,13 class queue(object):
             absf = repo.wjoin(f)
             if os.path.lexists(absf):
                 self.ui.note(_('saving current version of %s as %s\n') %
-                             (f, f + '.orig'))
+                             (f, cmdutil.origpath(self.ui, repo, f)))
+
+                absorig = cmdutil.origpath(self.ui, repo, absf)
                 if copy:
-                    util.copyfile(absf, absf + '.orig')
+                    util.copyfile(absf, absorig)
                 else:
-                    util.rename(absf, absf + '.orig')
+                    util.rename(absf, absorig)
 
     def printdiff(self, repo, diffopts, node1, node2=None, files=None,
                   fp=None, changes=None, opts={}):

tests/test-mq-qpush-fail.t

@@ -444,7 +444,7 test mq.keepchanges setting
   $ hg st a
   M a
   $ echo b >> b
-  $ hg --config mq.keepchanges=1 qpop --force
+  $ hg --config mq.keepchanges=1 qpop --force --config 'ui.origbackuppath=.hg/origbackups'
   popping p3
   now at: p2
   $ hg st b
@@ -461,4 +461,10 test mq.keepchanges setting
   now at: p2
   $ hg st a
 
+test previous qpop (with --force and --config) saved .orig files to where user
+wants them
+  $ ls .hg/origbackups
+  b.orig
+  $ rm -rf .hg/origbackups
+
   $ cd ..

tests/test-mq.t

@@ -1394,9 +1394,10 qpush should fail, local changes
 
 apply force, should discard changes in hello, but not bye
 
-  $ hg qpush -f --verbose
+  $ hg qpush -f --verbose --config 'ui.origbackuppath=.hg/origbackups'
   applying empty
-  saving current version of hello.txt as hello.txt.orig
+  creating directory: $TESTTMP/forcepush/.hg/origbackups
+  saving current version of hello.txt as $TESTTMP/forcepush/.hg/origbackups/hello.txt.orig
   patching file hello.txt
   committing files:
   hello.txt
@@ -1405,7 +1406,6 apply force, should discard changes in h
   now at: empty
   $ hg st
   M bye.txt
-  ? hello.txt.orig
   $ hg diff --config diff.nodates=True
   diff -r ba252371dbc1 bye.txt
   --- a/bye.txt
@@ -1428,6 +1428,10 apply force, should discard changes in h
   +world
   +universe
 
+test that the previous call to qpush with -f (--force) and --config actually put
+the orig files out of the working copy
+  $ ls .hg/origbackups
+  hello.txt.orig
 
 test popping revisions not in working dir ancestry