Re: Destructive side-effect of "cg-status"

From: Linus Torvalds <torvalds@osdl.org>
Date: Oct 1, 2005, 16:41 UTC
Message-ID: <Pine.LNX.4.64.0510010934290.3378@g5.osdl.org>
In-Reply-To: <20050930160353.F025C352B7B@atlas.denx.de>

On Fri, 30 Sep 2005, Wolfgang Denk wrote:

Show 5 quoted lines

>
> So far I  thought  "cg-status"  is  a  harmless  command  which  just
> displays  some  status information. It ain't so. One of our engineers
> reported a  corrupted  repository  after  I  ran  "cg-status"  in  his
> directory:

Well, it's not corrupted, but yes, the index file ends up unreadable.

> That means, that "cg-status" actually *rewrote* .git/index,  with  me
> (wd)  as  new  owner, and - ignoring my umask - with permissions that
> prevent the original owner (sr) to access the file!

The umask thing looks like a bug. Fixed thus.

Also, arguably we should try to avoid writing the index file when not necessary, although the fact is, that cg-status (and "git status") _do_ need to actually keep it up-to-date in order to do the right thing. Also true of some other programs that might otherwise appear to be read-only (ie I've considered doing the same thing for "git diff").

We used to have that optimization, but it was broken. I fixed it but disabled it for fear of other bugs.

But honoring umask would seem to be a no-brainer.

		Linus

----

diff --git a/index.c b/index.c
--- a/index.c
+++ b/index.c
@@ -29,7 +29,7 @@ int hold_index_file_for_update(struct ca
 		signal(SIGINT, remove_lock_file_on_signal);
 		atexit(remove_lock_file);
 	}
-	return open(cf->lockfile, O_RDWR | O_CREAT | O_EXCL, 0600);
+	return open(cf->lockfile, O_RDWR | O_CREAT | O_EXCL, 0666);
 }
 
 int commit_index_file(struct cache_file *cf)