cmdserver: forcibly use L channel to read password input (issue3161)

Command server is designed to use the channel protocol even if the server
process is accessible to tty, whereas vanilla hg should be able to read
password from tty in that case.  So it isn't enough to swap sys.stdin:

    # works only if the server process is detached from the console
    sys.stdin = self.fin
    getpass.getpass('')
    sys.stdin = oldin

or test isatty:

    # vanilla hg can't talk to tty if stdin is redirected
    if self._isatty(self.fin):
        return getpass.getpass('')
    else:
        ...

Since ui.nontty flag is undocumented and command-server channels don't provide
isatty(), this change won't affect the other uses of ui._isatty().

issue3161 also suggests to provide some context of messages.  I think it can
be implemented by using the generic templating function.

mercurial/commandserver.py

@@ -187,14 +187,20 b' class server(object):'
         # copy the uis so changes (e.g. --config or --verbose) don't
         # persist between requests
         copiedui = self.ui.copy()
+        uis = [copiedui]
         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
+            uis.append(repoui)
             self.repo.ui = self.repo.dirstate._ui = repoui
             self.repo.invalidateall()
 
+        for ui in uis:
+            # any kind of interaction must use server channels
+            ui.setconfig('ui', 'nontty', 'true', 'commandserver')
+
         req = dispatch.request(args[:], copiedui, self.repo, self.cin,
                                self.cout, self.cerr)
 

mercurial/ui.py

@@ -689,7 +689,12 b' class ui(object):'
             return default
         try:
             self.write_err(self.label(prompt or _('password: '), 'ui.prompt'))
-            return getpass.getpass('')
+            # disable getpass() only if explicitly specified. it's still valid
+            # to interact with tty even if fin is not a tty.
+            if self.configbool('ui', 'nontty'):
+                return self.fin.readline().rstrip('\n')
+            else:
+                return getpass.getpass('')
         except EOFError:
             raise util.Abort(_('response expected'))
     def status(self, *msg, **opts):

tests/test-commandserver.py

@@ -294,6 +294,11 b' def mqoutsidechanges(server):'
     # repo.mq should be recreated to point to new queue
     runcommand(server, ['qqueue', '--active'])
 
+def getpass(server):
+    readchannel(server)
+    runcommand(server, ['debuggetpass', '--config', 'ui.interactive=True'],
+               input=cStringIO.StringIO('1234\n'))
+
 def startwithoutrepo(server):
     readchannel(server)
     runcommand(server, ['init', 'repo2'])
@@ -334,6 +339,19 b" if __name__ == '__main__':"
     hgrc.write('[extensions]\nmq=\n')
     hgrc.close()
     check(mqoutsidechanges)
+    dbg = open('dbgui.py', 'w')
+    dbg.write('from mercurial import cmdutil, commands\n'
+              'commands.norepo += " debuggetpass"\n'
+              'cmdtable = {}\n'
+              'command = cmdutil.command(cmdtable)\n'
+              '@command("debuggetpass")\n'
+              'def debuggetpass(ui):\n'
+              '    ui.write("%s\\n" % ui.getpass())\n')
+    dbg.close()
+    hgrc = open('.hg/hgrc', 'a')
+    hgrc.write('[extensions]\ndbgui=dbgui.py\n')
+    hgrc.close()
+    check(getpass)
 
     os.chdir('..')
     check(hellomessage)

tests/test-commandserver.py.out

@@ -81,6 +81,7 b' defaults.tag=-d "0 0"'
 ui.slash=True
 ui.interactive=False
 ui.foo=bar
+ui.nontty=true
  runcommand init foo
  runcommand -R foo showconfig ui defaults
 defaults.backout=-d "0 0"
@@ -89,6 +90,7 b' defaults.shelve=--date "0 0"'
 defaults.tag=-d "0 0"
 ui.slash=True
 ui.interactive=False
+ui.nontty=true
 
 testing hookoutput:
 
@@ -238,6 +240,11 b' patch queue now empty'
  runcommand qqueue --active
 foo
 
+testing getpass:
+
+ runcommand debuggetpass --config ui.interactive=True
+password: 1234
+
 testing hellomessage:
 
 o, 'capabilities: getencoding runcommand\nencoding: ***'