restage: New git-annex command, handles restaging unlocked files

This is much easier and less failure-prone than having the user run
git update-index --refresh themselves.

Sponsored-by: Dartmouth College's DANDI project

Command/Restage.hs

@@ -0,0 +1,25 @@
+{- git-annex command
+ -
+ - Copyright 2022 Joey Hess <id@joeyh.name>
+ -
+ - Licensed under the GNU AGPL version 3 or higher.
+ -}
+
+module Command.Restage where
+
+import Command
+import qualified Annex
+import Annex.Link
+
+cmd :: Command
+cmd = command "restage" SectionPlumbing 
+	"estages unlocked files in the git index"
+	paramNothing (withParams seek)
+
+seek :: CmdParams -> CommandSeek
+seek = withNothing (commandAction start)
+
+start :: CommandStart
+start = starting "restage" (ActionItemOther Nothing) (SeekInput []) $ do
+	restagePointerFiles =<< Annex.gitRepo
+	next $ return True