Hi Jeff, On Wed, Nov 23, 2011 at 05:16:58PM -0500, Jeff King wrote: > On Wed, Nov 23, 2011 at 10:08:21AM +0100, Uwe Kleine-König wrote: > > > John and I wondered about git fetch overwriting local tags. I was sure > > enough to claim that git fetch won't overwrite local tags with remote > > tags having the same name. But after John pointed me to > > > > http://www.pythian.com/news/9067/on-the-perils-of-importing-remote-tags-in-git/ > > > > I tested that (using Debian's 1.7.7.3) and really, git does overwrite > > local tags. > > > > Here is my test script: > > [...] > > git fetch --tags ../a > > [...] > > Is this intended? > > Sort of. > > By default, "git fetch" will "auto-follow" tags; if you fetch a commit > which is pointed to by a tag, then git will fetch that tag, too. So > generally, you shouldn't need to specify "--tags" at all, because you > will already be getting the relevant tags. Hmm, if I do: mkdir a cd a echo some content > some_file git init git add some_file git commit -m 'some commit log' git tag some_tag cd .. mkdir b cd b echo some different content > another_file git init git add another_file git commit -m 'another commit log' git fetch ../a I don't get the tag. That's why I added --tags. I guess that's because some_tag is a lightweight tag. Hmm, but even if I change the command to create the tag to git tag -a -m 'tag desc' some_tag I don't get it without --tags?! > The "--tags" option, however, is a short-hand for saying "fetch all of > the tags", and is equivalent to providing the refspec: > > git fetch ../a refs/tags/*:refs/tags/* > > Which of course will update your local tags with similarly-named ones > from the remote. So in that sense, there is no bug, and it is working > as intended; the problem is that the author's intent was not the same as > your intent. :) > > I'm not sure why you're using "--tags" in the first place. That might > help us figure out if there's another way to do what you want that is > safer. > > That being said, it would be nice if "--tags" wasn't so surprising. > Three things that I think could help are: > > 1. We usually require a "+" on the refspec (or "--force") to update > non-fast-forward branches. But there is no such safety on tags > (which generally shouldn't be updated at all). Should we at least > be enforcing the same fast-forward rules on tag fetches (or even > something more strict, like forbidding tag update at all unless > forced)? That sounds fine for me. > 2. We don't keep a reflog on tags. Generally there's no point. But > it wouldn't be very expensive (since they don't usually change), > and could provide a safety mechanism here. I prefer 1, but that would be better than the current situation at least. > 3. Keeping tags from remotes in separate namespaces, but collating > them at lookup time. This has been discussed, and I think is > generally a fine idea, but nobody has moved forward with code. That's something that John said in our discussion, too. That's the suggestion I like the most. Best regards and thanks for your time, Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | http://www.pengutronix.de/ | -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html