Windows: Fix running of the pre-commit-annex hook.

Annex/Hook.hs

@@ -16,7 +16,6 @@ import qualified Git.Hook as Git
 import Config
 import qualified Annex
 import Utility.Shell
-import Utility.FileMode
 
 import qualified Data.Map as M
 
@@ -53,19 +52,16 @@ hookWarning h msg = do
  - the existing hooks are cached. -}
 runAnnexHook :: Git.Hook -> Annex ()
 runAnnexHook hook = do
-	cmd <- fromRepo $ Git.hookFile hook
 	m <- Annex.getState Annex.existinghooks
 	case M.lookup hook m of
-		Just True -> run cmd
+		Just True -> run
 		Just False -> noop
 		Nothing -> do
-			exists <- hookexists cmd
+			exists <- inRepo $ Git.hookExists hook
 			Annex.changeState $ \s -> s
 				{ Annex.existinghooks = M.insert hook exists m }
-			when exists $
-				run cmd
+			when exists run
   where
-	hookexists f = liftIO $ catchBoolIO $
-		isExecutable . fileMode <$> getFileStatus f
-	run cmd = unlessM (liftIO $ boolSystem cmd []) $
-		warning $ cmd ++ " failed"
+	run = unlessM (inRepo $ Git.runHook hook) $ do
+		h <- fromRepo $ Git.hookFile hook
+		warning $ h ++ " failed"

Git/Hook.hs

@@ -1,15 +1,20 @@
 {- git hooks
  -
- - Copyright 2013 Joey Hess <joey@kitenet.net>
+ - Copyright 2013-2015 Joey Hess <joey@kitenet.net>
  -
  - Licensed under the GNU GPL version 3 or higher.
  -}
 
+{-# LANGUAGE CPP #-}
+
 module Git.Hook where
 
 import Common
 import Git
 import Utility.Tmp
+#ifndef mingw32_HOST_OS
+import Utility.FileMode
+#endif
 
 data Hook = Hook
 	{ hookName :: FilePath
@@ -56,3 +61,37 @@ expectedContent :: Hook -> Repo -> IO Bool
 expectedContent h r = do
 	content <- readFile $ hookFile h r
 	return $ content == hookScript h
+
+hookExists :: Hook -> Repo -> IO Bool
+hookExists h r = do
+	let f = hookFile h r
+	catchBoolIO $
+#ifndef mingw32_HOST_OS
+		isExecutable . fileMode <$> getFileStatus f
+#else
+		doesFileExist f
+#endif
+
+runHook :: Hook -> Repo -> IO Bool
+runHook h r = do
+	let f = hookFile h r
+	(c, ps) <- findcmd f
+	boolSystem c ps
+  where
+#ifndef mingw32_HOST_OS
+	findcmd = defcmd
+#else
+	{- Like msysgit, parse the first line of the hook file,
+	 - look for "#!", and dispatch the interpreter on the file. -}
+	findcmd f = do
+		l <- headMaybe . lines <$> catchDefaultIO "" (readFile f)
+		case l of
+			Just ('#':'!':rest) -> case words rest of
+				[] -> defcmd f
+				(c:ps) -> do
+					let ps' = map Param (ps ++ [f])
+					ok <- inPath c
+					return (if ok then c else takeFileName c, ps')
+			_ -> defcmd f
+#endif
+	defcmd f = return (f, [])

debian/changelog

@@ -12,6 +12,7 @@ git-annex (5.20150114) UNRELEASED; urgency=medium
   * Fix build failure when wget is not installed.
   * Fix wording of message displayed when unable to get a file that
     is available in untrusted repositories.
+  * Windows: Fix running of the pre-commit-annex hook.
 
  -- Joey Hess <id@joeyh.name>  Tue, 13 Jan 2015 17:03:39 -0400
 

doc/bugs/windows_isExecutable_fail.mdwn

@@ -0,0 +1,27 @@
+On Windows, isExecutable fails to detect a file that is indeed executable
+as such. This prevents git-annex from running the pre-commit-hook
+on Windows.
+
+getFileStatus yields a fileMode of 100666, which is 
+clearly a dummy mode. Not surprising, since unix-compat is partial stubs
+on windows.
+
+Actually, isExecutable is ok (it needs to check unix modes because it is
+used on file modes coming out of git). But, getFileStatus is the wrong
+thing to be using on Windows to check if a hook exists and is executable.
+
+I don't see anything in Win32 or Win32-extras on hackage that can check 
+executablility. Looking at git's source, it uses `access(path, X_OK) < 0`;
+haskell equivilant is System.Posix.Files.fileAccess, but the version
+in unix-compat has the same problem as checking getFileStatus's fileMode.
+
+I think it's reasonable to assume that if a hook exists on windows, it's
+intended to be executable, and try to run it. Actually, testing with
+msysgit, it runs hooks whether or not they have the execute bit set!
+So, done that now.
+
+However, now git-annex tries to run the hook but fails when it's a shell 
+script because #!/bin/sh is useless on windows. It looks to me like msysgit
+runs "sh hook" to work around that, and it is in fact parsing the shebang
+line and dispatching the interpreter. Ugh. (Also, pre-commit.bat doesn't
+get run.) Ok, added this same hack to git-annex. [[done]] --[[Joey]]

doc/tips/automatically_adding_metadata/comment_6_34f0c55d09ddee3de642f6b25a9f6269._comment

@@ -0,0 +1,9 @@
+[[!comment format=mdwn
+ username="joey"
+ subject="""comment 6"""
+ date="2015-01-20T17:19:34Z"
+ content="""
+@Michele after testing, git-annex on Windows seems to not see a file that
+does have the executable bit set as executable. I have opened a bug report
+[[bugs/windows_isExecutable_fail]], and worked around the problem now.
+"""]]