add exportedtree to info

info: When used with an exporttree remote, includes an "exportedtree" info,
which is the tree last exported to the remote. During an export conflict,
multiple values will be listed.

This commit was sponsored by John Pellman on Patreon.

Remote/Helper/Export.hs

@@ -18,6 +18,8 @@ import Remote.Helper.Encryptable (isEncrypted)
 import Database.Export
 import Annex.Export
 import Config
+import Git.Types (fromRef)
+import Logs.Export
 
 import qualified Data.Map as M
 import Control.Concurrent.STM
@@ -186,8 +188,11 @@ adjustExportable r = case M.lookup "exporttree" (config r) of
 			, checkPresentCheap = False
 			, mkUnavailable = return Nothing
 			, getInfo = do
+				ts <- map (\t -> ("exportedtree", fromRef t) )
+					. map exportedTreeish
+					<$> getExport (uuid r)
 				is <- getInfo r
-				return (is++[("export", "yes")])
+				return (is++[("export", "yes")]++ts)
 			}
 	retrieveKeyFileFromExport getexportlocs exportinconflict k _af dest p = unVerified $
 		if maybe False (isJust . verifyKeyContent) (maybeLookupBackendVariety (keyVariety k))