cmdserver: allow to start server without repository

Typical use case is to clone repository through command server.  Clone may
require user interaction, so command-server protocol is beneficial over
raw stdio channels.

mercurial/commands.py

@@ -5168,7 +5168,6 @@ def serve(ui, repo, **opts):
         s.serve_forever()
 
     if opts["cmdserver"]:
-        checkrepo()
         s = commandserver.server(ui, repo, opts["cmdserver"])
         return s.serve()
 

mercurial/commandserver.py

@@ -142,11 +142,15 @@ class server(object):
             else:
                 logfile = open(logpath, 'a')
 
-        # the ui here is really the repo ui so take its baseui so we don't end
-        # up with its local configuration
-        self.ui = repo.baseui
-        self.repo = repo
-        self.repoui = repo.ui
+        if repo:
+            # the ui here is really the repo ui so take its baseui so we don't
+            # end up with its local configuration
+            self.ui = repo.baseui
+            self.repo = repo
+            self.repoui = repo.ui
+        else:
+            self.ui = ui
+            self.repo = self.repoui = None
 
         if mode == 'pipe':
             self.cerr = channeledoutput(sys.stderr, sys.stdout, 'e')
@@ -183,12 +187,13 @@ class server(object):
         # copy the uis so changes (e.g. --config or --verbose) don't
         # persist between requests
         copiedui = self.ui.copy()
-        self.repo.baseui = copiedui
-        # clone ui without using ui.copy because this is protected
-        repoui = self.repoui.__class__(self.repoui)
-        repoui.copy = copiedui.copy # redo copy protection
-        self.repo.ui = self.repo.dirstate._ui = repoui
-        self.repo.invalidateall()
+        if self.repo:
+            self.repo.baseui = copiedui
+            # clone ui without using ui.copy because this is protected
+            repoui = self.repoui.__class__(self.repoui)
+            repoui.copy = copiedui.copy # redo copy protection
+            self.repo.ui = self.repo.dirstate._ui = repoui
+            self.repo.invalidateall()
 
         req = dispatch.request(args[:], copiedui, self.repo, self.cin,
                                self.cout, self.cerr)

tests/test-commandserver.py

@@ -294,6 +294,11 @@ def mqoutsidechanges(server):
     # repo.mq should be recreated to point to new queue
     runcommand(server, ['qqueue', '--active'])
 
+def startwithoutrepo(server):
+    readchannel(server)
+    runcommand(server, ['init', 'repo2'])
+    runcommand(server, ['id', '-R', 'repo2'])
+
 if __name__ == '__main__':
     os.system('hg init repo')
     os.chdir('repo')
@@ -329,3 +334,7 @@ if __name__ == '__main__':
     hgrc.write('[extensions]\nmq=\n')
     hgrc.close()
     check(mqoutsidechanges)
+
+    os.chdir('..')
+    check(hellomessage)
+    check(startwithoutrepo)

tests/test-commandserver.py.out

@@ -237,3 +237,16 @@ popping 0.diff
 patch queue now empty
  runcommand qqueue --active
 foo
+
+testing hellomessage:
+
+o, 'capabilities: getencoding runcommand\nencoding: ***'
+ runcommand id
+abort: there is no Mercurial repository here (.hg not found)
+ [255]
+
+testing startwithoutrepo:
+
+ runcommand init repo2
+ runcommand id -R repo2
+000000000000 tip