init: Install working hook scripts when run on a crippled filesystem and on Windows

Annex/Hook.hs

@@ -13,7 +13,6 @@ module Annex.Hook where
 
 import Annex.Common
 import qualified Git.Hook as Git
-import Config
 import qualified Annex
 import Utility.Shell
 
@@ -57,11 +56,8 @@ mkHookScript s = unlines
 	]
 
 hookWrite :: Git.Hook -> Annex ()
-hookWrite h = 
-	-- cannot have git hooks in a crippled filesystem (no execute bit)
-	unlessM crippledFileSystem $
-		unlessM (inRepo $ Git.hookWrite h) $
-			hookWarning h "already exists, not configuring"
+hookWrite h = unlessM (inRepo $ Git.hookWrite h) $
+	hookWarning h "already exists, not configuring"
 
 hookUnWrite :: Git.Hook -> Annex ()
 hookUnWrite h = unlessM (inRepo $ Git.hookUnWrite h) $

CHANGELOG

@@ -23,6 +23,10 @@ git-annex (7.20190731) UNRELEASED; urgency=medium
     it applies the same adjustment to the branch before merging it.
   * test: Add pass using adjusted unlocked branch.
   * Fix some test suite failures on Windows.
+  * init: Install working hook scripts when run on a crippled filesystem
+    and on Windows. If your repository was set up by an old version
+    of git-annex that omitted the hooks, you can simply re-run git-annex init
+    to install them.
 
  -- Joey Hess <id@joeyh.name>  Thu, 01 Aug 2019 00:11:56 -0400
 

Git/Hook.hs

@@ -31,7 +31,18 @@ hookFile :: Hook -> Repo -> FilePath
 hookFile h r = localGitDir r </> "hooks" </> hookName h
 
 {- Writes a hook. Returns False if the hook already exists with a different
- - content. Upgrades old scripts. -}
+ - content. Upgrades old scripts.
+ -
+ - This can install hooks on both filesystem like FAT that do not support
+ - execute bits, and on Windows.
+ -
+ - If the filesystem does not support execute bits, it's typically mounted
+ - such that all files have the execute bit set. So just write the hook
+ - and ignore failure to make it executable.
+ -
+ - On Windows, git will run hooks that are not executable. The hook
+ - is run with a bundled bash, so should start with #!/bin/sh
+ -}
 hookWrite :: Hook -> Repo -> IO Bool
 hookWrite h r = ifM (doesFileExist f)
 	( expectedContent h r >>= \case
@@ -45,7 +56,7 @@ hookWrite h r = ifM (doesFileExist f)
 	go = do
 		viaTmp writeFile f (hookScript h)
 		p <- getPermissions f
-		setPermissions f $ p {executable = True}
+		void $ tryIO $ setPermissions f $ p {executable = True}
 		return True
 
 {- Removes a hook. Returns False if the hook contained something else, and

doc/bugs/windows_fails_import_export_tests.mdwn

@@ -1,27 +1,30 @@
-Two test failures on windows in the import/export tests. The tests fail on
-a v7 adjusted unlocked branch, but pass a direct mode. It may be that
-there's a problem with the tests outside of windows on an adjusted branch.
+Windows test suite fails the import/export tests.
 
-The first test fails to export all annexed files to a directory special
-remote.
+It imports a file, but the worktree file remains a unlocked pointer
+file. So the test fails. Running `git annex smudge--update` fixed the
+file content. 
 
-	export foo sha1foo failed
+Reproduced outside the test suite, and tried with GIT_TRACE=1.
+When `git-annex merge remote/master``runs git merge, it does then smudge
+--clean the imported files. But smudge --update does not get run. The
+post-merge hook should run it.
 
-No indication of why it failed.
+Ahh -- on windows, hooks are not written, because the code skips that
+for a crippled filesystem, assuming it has no execute bit.
 
-> Update: Now it shows the problem, which is that the exported file is
-> locked so statting it fails. --[[Joey]]
+So, this is both a problem on windows and on crippled filesystems.
+The user needs to run smudge --update themselves, or maybe git-annex
+can do it sometimes. Eg, `git annex merge` (and sync) could certianly
+smudge --update when on a crippled filesystem. And that would be
+enough to fix the test suite.
 
-The second test fails in an import. It gets as far as updating foo/master,
-but then when it tries to merge that branch, there's a merge conflict.
-That merge conflict seems very likely due to being on an adjusted branch;
-foo/master will have the non-adjusted version of the file and merging it
-into a branch where it's been adjusted does sound like there could be a
-legitimate merge conflict.
+But if a user is on a crippled filesystem with an adjusted branch, and
+they do some other operation that would be covered by post-merge or
+post-checkout hook, they will be surprised to find unpopulated pointer
+files in the working tree.
 
-If so, note that the git-annex-import man page suggests doing just such a
-merge, so perhaps the docs will need to be updated, if some git-annex
-command is instead used to do the merge. --[[Joey]]
-
-> Probably down to only one test failure now after some fixes. Have not
-> checked. --[[Joey]]
+I think this can be avoided. On eg fat on linux, all files are executable,
+so the hook can be installed and will work. On Windows, a hook can start
+with #!/bin/sh and not be executable, and will be run by the bash bundled
+with git for windows.
+--[[Joey]]