make --batch honor matching options

When --batch is used with matching options like --in, --metadata, etc, only
operate on the provided files when they match those options. Otherwise, a
blank line is output in the batch protocol.

Affected commands: find, add, whereis, drop, copy, move, get

In the case of find, the documentation for --batch already said it honored
the matching options. The docs for the rest didn't, but it makes sense to
have them honor them. While this is a behavior change, why specify the
matching options with --batch if you didn't want them to apply?

Note that the batch output for all of the affected commands could
already output a blank line in other cases, so batch users should
already be prepared to deal with it.

git-annex metadata didn't seem worth making support the matching options,
since all it does is output metadata or set metadata, the use cases for
using it in combination with the martching options seem small. Made it
refuse to run when they're combined, leaving open the possibility for later
support if a use case develops.

This commit was sponsored by Brett Eisenberg on Patreon.

CmdLine/Batch.hs

@@ -12,6 +12,8 @@ import Types.Command
 import CmdLine.Action
 import CmdLine.GitAnnex.Options
 import Options.Applicative
+import Limit
+import Types.FileMatcher
 
 data BatchMode = Batch | NoBatch
 
@@ -72,5 +74,18 @@ batchCommandAction a = maybe (batchBadInput Batch) (const noop)
 
 -- Reads lines of batch input and passes the filepaths to a CommandStart
 -- to handle them.
-batchFiles :: (FilePath -> CommandStart) -> Annex ()
-batchFiles a = batchInput Right $ batchCommandAction . a
+--
+-- File matching options are not checked.
+allBatchFiles :: (FilePath -> CommandStart) -> Annex ()
+allBatchFiles a = batchInput Right $ batchCommandAction . a
+
+-- Like allBatchFiles, but checks the file matching options
+-- and skips non-matching files.
+batchFilesMatching :: (FilePath -> CommandStart) -> Annex ()
+batchFilesMatching a = do
+	matcher <- getMatcher
+	allBatchFiles $ \f ->
+		ifM (matcher $ MatchingFile $ FileInfo f f)
+			( a f
+			, return Nothing
+			)