Support checking ftp urls for file presence.

Utility/Url.hs

@@ -123,10 +123,14 @@ getUrlInfo url uo = case parseURIRelaxed url of
 			| Build.SysConfig.curl -> do
 				output <- catchDefaultIO "" $
 					readProcess "curl" $ toCommand curlparams
+				let len = extractlencurl output
+				let good = found len Nothing
 				case lastMaybe (lines output) of
-					Just ('2':_:_) -> found
-						(extractlencurl output)
-						Nothing
+					Just ('2':_:_) -> good
+					-- don't try to parse ftp status
+					-- codes; if curl got a length,
+					-- it's good
+					_ | "ftp" `isInfixOf` uriScheme u && isJust len -> good
 					_ -> dne
 			| otherwise -> dne
 	Nothing -> dne

debian/changelog

@@ -29,6 +29,7 @@ git-annex (5.20150421) UNRELEASED; urgency=medium
   * Android: Updated bundled ssh from 6.1p1 to 6.4p1.
   * Work around wget bug #784348 which could cause it to clobber git-annex
     symlinks when downloading from ftp.
+  * Support checking ftp urls for file presence.
 
  -- Joey Hess <id@joeyh.name>  Tue, 21 Apr 2015 15:54:10 -0400
 

doc/bugs/git-annex_deletes_file_when_using___34__git_annex_get__34___after___34__git_annex_addurl_--file__34__.mdwn

@@ -105,3 +105,8 @@ $
 """]]
 
 > workaround in place; [[done]] --[[Joey]]
+
+> Also, fixed it to allow dropping the file if the ftp server seems 
+> to reply with a successful result (it's replying with 350, which is not
+> unambiguously good, but since curl is able to get the right file length,
+> the file is presumably still on the ftp server. --[[Joey]]