On Fri, Nov 7, 2014 at 3:38 PM, Jeff King <peff@xxxxxxxx> wrote: > On Fri, Nov 07, 2014 at 03:13:24AM -0500, Jeff King wrote: > >> I noticed that "git checkout $tree -- $path" will _always_ unlink and >> write a new copy of each matching path, even if they are up-to-date with >> the index and the content in $tree is the same. > > By the way, one other thing I wondered while looking at this code: when > we checkout a working tree file, we unlink the old one and write the new > one in-place. Is there a particular reason we do this versus writing to > a temporary file and renaming it into place? That would give > simultaneous readers a more atomic view. > > I suspect the answer is something like: you cannot always do a rename, > because you might have a typechange, directory becoming a file, or vice > versa; so anyone relying on an atomic view during a checkout operation > is already Doing It Wrong. Handling a content-change of an existing > path would complicate the code, so we do not bother. Not a confirmation, but it looks like Linus did it just to make sure he had new permissions right, in e447947 (Be much more liberal about the file mode bits. - 2005-04-16). -- Duy -- 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