Windows: Fix handling of absolute unix-style git repository paths.

Note that on Windows a remote with a path like /home/foo/bar
is interpreted by git as being some screwy relative path (relative to what
exactly seems ill-defined -- it seemed relative to C:\Program Files\Git\ in
my tests!) So no attempt has been made to handle such a path sanely, just not
to crash when encountering it.

Note that "C:\\foo" </> "/home/foo/bar" yields /home/foo/bar even though
that is not absolute! I don't know what to make of all this,
except that I will be very happy when this crock of **** vanishes from
the face of the earth.

CmdLine/GitAnnexShell/Fields.hs

@@ -9,6 +9,7 @@ module CmdLine.GitAnnexShell.Fields where
 
 import Common.Annex
 import qualified Annex
+import Git.FilePath
 
 import Data.Char
 
@@ -29,7 +30,7 @@ remoteUUID = Field "remoteuuid" $
 associatedFile :: Field
 associatedFile = Field "associatedfile" $ \f ->
 	-- is the file a safe relative filename?
-	not (isAbsolute f) && not ("../" `isPrefixOf` f)
+	not (absoluteGitPath f) && not ("../" `isPrefixOf` f)
 
 direct :: Field
 direct = Field "direct" $ \f -> f == "1"