From 2686d2d7ea44d9b5d8243da6fc9f2df1d2441a71 Mon Sep 17 00:00:00 2001
From: Joey Hess <joeyh@joeyh.name>
Date: Thu, 21 Aug 2025 11:04:26 -0400
Subject: [PATCH] Removed support for git versions older than 2.5.

This entirely removes Git.BuildVersion, which avoids the possibility that
git-annex will behave differently based on the version of git it was built
with, rather than the version it's used with.

Debian oldoldstable is the oldest version of git that git-annex needs to
support, since it's used in the amd64ancient build.

cabal configure will fail if the git version is too old.

Sponsored-by: Nicholas Golder-Manning
---
 Build/Configure.hs  |  2 +-
 CHANGELOG           |  1 +
 Command/Smudge.hs   | 11 +----------
 Git/BuildVersion.hs | 21 ---------------------
 Git/CatFile.hs      | 13 ++++---------
 git-annex.cabal     |  1 -
 6 files changed, 7 insertions(+), 42 deletions(-)
 delete mode 100644 Git/BuildVersion.hs

diff --git a/Build/Configure.hs b/Build/Configure.hs
index 2c848ce965..c8bebaaba6 100644
--- a/Build/Configure.hs
+++ b/Build/Configure.hs
@@ -81,7 +81,7 @@ getGitVersion = go =<< getEnv "FORCE_GIT_VERSION"
 	go (Just s) = return $ Config "gitversion" $ StringConfig s
 	go Nothing = do
 		v <- Git.Version.installed
-		let oldestallowed = Git.Version.normalize "2.1"
+		let oldestallowed = Git.Version.normalize "2.5"
 		when (v < oldestallowed) $
 			error $ "installed git version " ++ show v ++ " is too old! (Need " ++ show oldestallowed ++ " or newer)"
 		return $ Config "gitversion" $ StringConfig $ show v
diff --git a/CHANGELOG b/CHANGELOG
index b7ce9fc91f..7717641e64 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -26,6 +26,7 @@ git-annex (10.20250722) UNRELEASED; urgency=medium
     for exporttree=yes/importtree=yes remotes.
   * Bump aws build dependency to 0.24.1.
   * stack.yaml: Update to lts-24.2.
+  * Removed support for git versions older than 2.5.
 
  -- Joey Hess <id@joeyh.name>  Wed, 30 Jul 2025 13:45:42 -0400
 
diff --git a/Command/Smudge.hs b/Command/Smudge.hs
index dc3854a661..c381c0aa5a 100644
--- a/Command/Smudge.hs
+++ b/Command/Smudge.hs
@@ -19,7 +19,6 @@ import Annex.WorkTree
 import Logs.Smudge
 import Logs.Location
 import qualified Database.Keys
-import qualified Git.BuildVersion
 import Git.FilePath
 import Git.Types
 import Git.HashObject
@@ -97,15 +96,7 @@ clean file = do
 	Annex.BranchState.disableUpdate -- optimisation
 	b <- liftIO $ L.hGetContents stdin
 	let passthrough = liftIO $ L.hPut stdout b
-	-- Before git 2.5, failing to consume all stdin here would
-	-- cause a SIGPIPE and crash it.
-	-- Newer git catches the signal and stops sending, which is
-	-- much faster. (Also, git seems to forget to free memory
-	-- when sending the file, so the less we let it send, the
-	-- less memory it will waste.)
-	let discardreststdin = if Git.BuildVersion.older "2.5"
-		then L.length b `seq` return ()
-		else liftIO $ hClose stdin
+	let discardreststdin = liftIO $ hClose stdin
 	let emitpointer = liftIO . S.hPut stdout . formatPointer
 	clean' file (parseLinkTargetOrPointerLazy' b)
 		passthrough
diff --git a/Git/BuildVersion.hs b/Git/BuildVersion.hs
deleted file mode 100644
index f94a892015..0000000000
--- a/Git/BuildVersion.hs
+++ /dev/null
@@ -1,21 +0,0 @@
-{- git build version
- -
- - Copyright 2011 Joey Hess <id@joeyh.name>
- -
- - Licensed under the GNU AGPL version 3 or higher.
- -}
-
-module Git.BuildVersion where
-
-import Git.Version
-import qualified BuildInfo
-
-{- Using the version it was configured for avoids running git to check its
- - version, at the cost that upgrading git won't be noticed.
- - This is only acceptable because it's rare that git's version influences
- - code's behavior. -}
-buildVersion :: GitVersion
-buildVersion = normalize BuildInfo.gitversion
-
-older :: String -> Bool
-older n = buildVersion < normalize n 
diff --git a/Git/CatFile.hs b/Git/CatFile.hs
index 877186a1ae..a0ab796183 100644
--- a/Git/CatFile.hs
+++ b/Git/CatFile.hs
@@ -54,7 +54,6 @@ import Git.Types
 import Git.HashObject
 import qualified Git.LsTree as LsTree
 import qualified Utility.CoProcess as CoProcess
-import qualified Git.BuildVersion as BuildVersion
 import Utility.Tuple
 
 data CatFileHandle = CatFileHandle 
@@ -403,14 +402,10 @@ withCatFileStream
 withCatFileStream check repo reader = assertLocal repo $
 	bracketIO start stop $ \(c, hin, hout, _) -> reader c hin hout
   where
-	params = catMaybes
-		[ Just $ Param "cat-file"
-		, Just $ Param ("--batch" ++ (if check then "-check" else "") ++ "=" ++ batchFormat)
-		-- This option makes it faster, but is not present in
-		-- older versions of git.
-		, if BuildVersion.older "2.4.3"
-			then Nothing
-			else Just $ Param "--buffer"
+	params =
+		[ Param "cat-file"
+		, Param ("--batch" ++ (if check then "-check" else "") ++ "=" ++ batchFormat)
+		, Param "--buffer" -- makes it faster
 		]
 
 	start = do
diff --git a/git-annex.cabal b/git-annex.cabal
index bd678f1a5c..4fbf9f0f7f 100644
--- a/git-annex.cabal
+++ b/git-annex.cabal
@@ -813,7 +813,6 @@ Executable git-annex
     Git
     Git.AutoCorrect
     Git.Branch
-    Git.BuildVersion
     Git.Bundle
     Git.CatFile
     Git.CheckAttr