fix for Windows file timestamp timezone madness

On Windows, changing the time zone causes the apparent mtime of files to
change. This confuses git-annex, which natually thinks this means the files
have actually been modified (since THAT'S WHAT A MTIME IS FOR, BILL <sheesh>).

Work around this stupidity, by using the inode sentinal file to detect if
the timezone has changed, and calculate a TSDelta, which will be applied
when generating InodeCaches.

This should add no overhead at all on unix. Indeed, I sped up a few
things slightly in the refactoring.

Seems to basically work! But it has a big known problem:
If the timezone changes while the assistant (or a long-running command)
runs, it won't notice, since it only checks the inode cache once, and
so will use the old delta for all new inode caches it generates for new
files it's added. Which will result in them seeming changed the next time
it runs.

This commit was sponsored by Vincent Demeester.

1 files changed, 2 insertions, 2 deletions

diff --git a/Annex/Direct.hs b/Annex/Direct.hs
index 70188ea11..e3dbfb6d8 100644
--- a/Annex/Direct.hs
+++ b/Annex/Direct.hs
@@ -53,11 +53,11 @@ stageDirect = do
 	{- Determine what kind of modified or deleted file this is, as
 	 - efficiently as we can, by getting any key that's associated
 	 - with it in git, as well as its stat info. -}
-	go (file, Just sha, Just mode) = do
+	go (file, Just sha, Just mode) = withTSDelta $ \delta -> do
 		shakey <- catKey sha mode
 		mstat <- liftIO $ catchMaybeIO $ getSymbolicLinkStatus file
 		filekey <- isAnnexLink file
-		case (shakey, filekey, mstat, toInodeCache =<< mstat) of
+		case (shakey, filekey, mstat, toInodeCache delta =<< mstat) of
 			(_, Just key, _, _)
 				| shakey == filekey -> noop
 				{- A changed symlink. -}