diffdriver --text support options for diff

Sponsored-by: KDM on Patreon

Command/DiffDriver.hs

@@ -70,7 +70,9 @@ serializeReq req@(Req {}) = map Param
 
 parseReq :: Options -> (Req, Differ)
 parseReq opts
-	| textDiff opts = (mk (restOptions opts), textDiffer)
+	| textDiff opts = case separate (== "--") (restOptions opts) of
+		(_,[]) -> (mk (restOptions opts), textDiffer [])
+		(ps,rest) -> (mk rest, textDiffer ps)
 	| otherwise = case separate (== "--") (restOptions opts) of
 		(c:ps, l) -> (mk l, externalDiffer c ps)
 		([],_) -> badopts
@@ -117,13 +119,13 @@ fixupReq req@(Req {}) =
 externalDiffer :: String -> [String] -> Differ
 externalDiffer c ps = \req -> boolSystem c (map Param ps ++ serializeReq req )
 
-textDiffer :: Differ
+textDiffer :: [String] -> Differ
-textDiffer req = do
+textDiffer diffopts req = do
 	putStrLn ("diff a/" ++ rPath req ++ " b/" ++ rPath req)
 	-- diff exits nonzero on difference, so ignore exit status
-	void $ boolSystem "diff"
+	void $ boolSystem "diff" $
 		[ Param "-u"
 		, Param (rOldFile req)
 		, Param (rNewFile req)
-		]
+		] ++ map Param diffopts
 	return True

doc/git-annex-diffdriver.mdwn

@@ -4,7 +4,7 @@ git-annex diffdriver - git diff driver
 
 # SYNOPSIS
 
-git annex diffdriver --text
+git annex diffdriver --text [-- --opts --]
 
 git annex diffdriver `-- cmd --opts --`
 
@@ -42,6 +42,7 @@ set `GIT_EXTERNAL_DIFF="git-annex diffdriver -- j-c-diff --"`
 # OPTIONS
 
 To diff text files with diff(1), use the "--text" option.
+To pass additional options to diff(1), use eg "--text -- --color --"
 
 To use an external diff driver command, the options must start with
 "--" followed by the diff driver command, its options, and another "--"

doc/todo/Improving_diffdriver_--text.mdwn

@@ -28,3 +28,5 @@ How about having `git annex diffdriver --text` always using `diff --text`? That
 Thanks again a ton for git-annex, the Tübix2023-Workshop was well appreciated and lots of fun. 👍
 
 Yann
+
+> [[done]] --[[Joey]]