avoid clobbering existing env

This is necessary on windows, ssh couldn't resolve hostnames without env
for whatever reason.

Assistant/WebApp/Configurators/Ssh.hs

@@ -31,6 +31,7 @@ import Config.Files
 import Utility.Tmp
 import Utility.FileMode
 import Utility.ThreadScheduler
+import Utility.Env
 
 #ifdef mingw32_HOST_OS
 import Utility.Rsync
@@ -344,7 +345,8 @@ sshAuthTranscript sshinput opts input = case inputAuthMethod sshinput of
 			Just pass -> withTmpFile "ssh" $ \passfile h -> do
 				hClose h
 				writeFileProtected passfile pass
-				let env =
+				env <- getEnvironment
+				let env' = addEntries
 					[ ("SSH_ASKPASS", program)
 					, (sshAskPassEnv, passfile)
 					-- ssh does not use SSH_ASKPASS
@@ -352,8 +354,8 @@ sshAuthTranscript sshinput opts input = case inputAuthMethod sshinput of
 					-- there is no controlling
 					-- terminal.
 					, ("DISPLAY", ":0")
-					]
-				go [passwordprompts 1] (Just env)	
+					] env
+				go [passwordprompts 1] (Just env')
 	
 	passwordprompts :: Int -> String
 	passwordprompts = sshOpt "NumberOfPasswordPrompts" . show

doc/design/assistant/sshpassword.mdwn

@@ -53,3 +53,17 @@ prompt the user for it before running ssh and the ssh-askpass shim.
 This avoids some complexity, and perhaps some attack vectors,
 if the shim cannot requst an arbitrary password prompt.
 (This complexity not needed with the temp file approach..)
+
+### TODO
+
+* Does not work on Windows; ssh still prompts in the terminal for the
+  password.
+* test on OSX
+* test on Android
+* enabling rsync repositories needs to prompt for password; currently
+  broken
+* test gcrypt repositories (creation of new and enabling)
+* If the user is slow, the cached ssh key can exire before they finish.
+  Currently this results in ssh being given no password, and failing.
+  Either avoid time-based expiry (manually expiring when done, and how
+  to detect if they gave up?) or notice this and give a sensible error.