mincopies

This is conceptually very simple, just making a 1 that was hard coded be
exposed as a config option. The hard part was plumbing all that, and
dealing with complexities like reading it from git attributes at the
same time that numcopies is read.

Behavior change: When numcopies is set to 0, git-annex used to drop
content without requiring any copies. Now to get that (highly unsafe)
behavior, mincopies also needs to be set to 0. It seemed better to
remove that edge case, than complicate mincopies by ignoring it when
numcopies is 0.

This commit was sponsored by Denis Dzyubenko on Patreon.

Command/NumCopies.hs

@@ -1,6 +1,6 @@
 {- git-annex command
  -
- - Copyright 2014 Joey Hess <id@joeyh.name>
+ - Copyright 2014-2021 Joey Hess <id@joeyh.name>
  -
  - Licensed under the GNU AGPL version 3 or higher.
  -}
@@ -20,17 +20,20 @@ seek :: CmdParams -> CommandSeek
 seek = withWords (commandAction . start)
 
 start :: [String] -> CommandStart
-start [] = startGet
-start [s] = case readish s of
+start = start' "numcopies" startGet startSet
+
+start' :: String -> CommandStart -> (Int -> CommandStart) -> [String] -> CommandStart
+start' _ startget _ [] = startget
+start' setting _ startset [s] = case readish s of
 	Nothing -> giveup $ "Bad number: " ++ s
 	Just n
-		| n > 0 -> startSet n
+		| n > 0 -> startset n
 		| n == 0 -> ifM (Annex.getState Annex.force)
-			( startSet n
-			, giveup "Setting numcopies to 0 is very unsafe. You will lose data! If you really want to do that, specify --force."
+			( startset n
+			, giveup $ "Setting " ++ setting ++ " to 0 is very unsafe. You will lose data! If you really want to do that, specify --force."
 			)
 		| otherwise -> giveup "Number cannot be negative!"
-start _ = giveup "Specify a single number."
+start' _ _ _ _ = giveup "Specify a single number."
 
 startGet :: CommandStart
 startGet = startingCustomOutput (ActionItemOther Nothing) $ next $ do