> -----Original Message----- > From: git-owner@xxxxxxxxxxxxxxx [mailto:git-owner@xxxxxxxxxxxxxxx] On > Behalf Of Duy Nguyen > Sent: Wednesday, April 12, 2017 7:21 AM > To: Kevin Willford <kewillf@xxxxxxxxxxxxx> > Cc: Kevin Willford <kcwillford@xxxxxxxxx>; git@xxxxxxxxxxxxxxx; > gitster@xxxxxxxxx; peff@xxxxxxxx > Subject: Re: [PATCH 3/3] reset.c: update files when using sparse to avoid > data loss. > > On Wed, Apr 12, 2017 at 5:30 AM, Kevin Willford <kewillf@xxxxxxxxxxxxx> > wrote: > > The loss of the skip-worktree bits is part of the problem if you are > > talking about modified files. The other issue that I was having is > > when running a reset and there were files added in the commit that is > > being reset, there will not be an entry in the index and not a file on > > disk so the data for that file is completely lost at that point. > > "status" also doesn't include anything about this loss of data. On > > modified files status will at least have the file as deleted since > > there is still an index entry but again the previous version of the file and it's > data is lost. > > Well, we could have "deleted" index entries, those marked with > CE_REMOVE. They are never written down to file though, so 'status' > won't benefit from that. Hopefully we can restore the file before the index > file is written down and we really lose skip-worktree bits? Because this is a reset --mixed it will never run through unpack_trees and The entries are never marked with CE_REMOVE. > > > To me this is totally unexpected behavior, for example if I am on a > > commit where there are only files that where added and run a reset > > HEAD~1 and then a status, it will show a clean working directory. > > Regardless of skip-worktree bits the user needs to have the data in > > the working directory after the reset or data is lost which is always bad. > > I agree we no longer have a place to save the skip-worktree bit, we have to > restore the state back as if skip-worktree bit does not exist. > It would be good if we could keep the logic in unpack_trees() though. > For example, if the file is present on disk even if skip-worktree bit is on, > unpack_trees() would abort instead of silently overwriting it. > This is a difference between skip-worktree and assume-unchanged bits. > If you do explicit checkout_entry() you might have to add more checks to > keep behavior consistent. > -- > Duy Because this is a reset --mixed it will follow the code path calling read_from_tree and ends up calling update_index_from_diff in the format_callback of the diff, so unpack_trees() is never called in the --mixed case. This code change also only applies when the file does not exist and the skip-worktree bit is on and the updated index entry either will be missing (covers the added scenario) or was not missing before (covers the modified scenario). If there is a better way to get the previous index entry to disk than what I am doing, I am happy to implement it correctly. Thanks, Kevin