From bb86eebfbd2ae01b19bf0d5c22ea8a0d0287c18c Mon Sep 17 00:00:00 2001
From: Joey Hess <joeyh@joeyh.name>
Date: Fri, 13 Nov 2015 13:35:29 -0400
Subject: [PATCH] init: Automatically enable annex.pidlock when necessary.

---
 Annex/Init.hs    | 29 ++++++++++++++++++++++++++++-
 debian/changelog |  1 +
 2 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/Annex/Init.hs b/Annex/Init.hs
index 03915904e0..65e9aa474a 100644
--- a/Annex/Init.hs
+++ b/Annex/Init.hs
@@ -41,6 +41,7 @@ import Utility.UserInfo
 import Utility.FileMode
 import Annex.Perms
 import System.Posix.User
+import qualified Utility.LockFile.Posix as Posix
 #endif
 
 genDescription :: Maybe String -> Annex String
@@ -74,9 +75,11 @@ initialize mdescription = do
 	u <- getUUID
 	describeUUID u =<< genDescription mdescription
 
--- Everything except for uuid setup.
+-- Everything except for uuid setup, shared clone setup, and initial
+-- description.
 initialize' :: Annex ()
 initialize' = do
+	checkLockSupport
 	checkFifoSupport
 	checkCrippledFileSystem
 	unlessM isBare $
@@ -167,6 +170,24 @@ checkCrippledFileSystem = whenM probeCrippledFileSystem $ do
 		setConfig (ConfigKey "core.symlinks")
 			(Git.Config.boolConfig False)
 
+probeLockSupport :: Annex Bool
+probeLockSupport = do
+#ifdef mingw32_HOST_OS
+	return True
+#else
+	tmp <- fromRepo gitAnnexTmpMiscDir
+	let f = tmp </> "lockprobe"
+	createAnnexDirectory tmp
+	mode <- annexFileMode
+	liftIO $ do
+		nukeFile f
+		ok <- catchBoolIO $ do
+			Posix.dropLock =<< Posix.lockExclusive (Just mode) f
+			return True
+		nukeFile f
+		return ok
+#endif
+
 probeFifoSupport :: Annex Bool
 probeFifoSupport = do
 #ifdef mingw32_HOST_OS
@@ -188,6 +209,12 @@ probeFifoSupport = do
 		return $ either (const False) isNamedPipe ms
 #endif
 
+checkLockSupport :: Annex ()
+checkLockSupport = unlessM probeLockSupport $ do
+	warning "Detected a filesystem without POSIX fcntl lock support."
+	warning "Enabling annex.pidlock."
+	setConfig (annexConfig "pidlock") (Git.Config.boolConfig True)
+
 checkFifoSupport :: Annex ()
 checkFifoSupport = unlessM probeFifoSupport $ do
 	warning "Detected a filesystem without fifo support."
diff --git a/debian/changelog b/debian/changelog
index 764823e6c2..1504c83ca1 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -29,6 +29,7 @@ git-annex (5.20151102.2) UNRELEASED; urgency=medium
     that were missed before.
   * Added annex.pidlock and annex.pidlocktimeout configuration to support
     filesystems where POSIX fcntl locks cannot be used.
+  * init: Automatically enable annex.pidlock when necessary.
 
  -- Joey Hess <id@joeyh.name>  Wed, 04 Nov 2015 12:50:20 -0400
 
-- 
2.30.2