On 7/28/2021 7:13 PM, Elijah Newren wrote: > On Mon, Jul 26, 2021 at 9:18 AM Derrick Stolee via GitGitGadget > <gitgitgadget@xxxxxxxxx> wrote: ... >> * a full proposal for what to do with "git (add|mv|rm)" and paths outside >> the cone is delayed to another series (with an RFC round) because the >> behavior of the sparse-index matches a full index with sparse-checkout. > > I think this makes sense. > > I've read through the patches, and I like this version...with one > exception. Can we mark the test added in patch 1 under > > # 3. Rename the file to another sparse filename and > # accept conflict markers as resolved content. > > as NEEDSWORK or even MAYNEEDWORK? I have no objection to adding a blurb such as: # NEEDSWORK: allowing adds outside the sparse cone can be # confusingto users, as the file can disappear from the # worktree without warning in later Git commands. And perhaps I'm misunderstanding the situation a bit, but that seems to apply not just to this third case, but all of them. I don't see why the untracked case is special compared to the tracked case. More investigation may be required on my part. > I'm still quite unconvinced that it > is testing for correct behavior, and don't want to paint ourselves > into a corner. In particular, we don't allow folks to "git add > $IGNORED_FILE" without a --force override because it's likely to be a > mistake. I agree about ignored files, and that is true whether or not they are in the sparse cone. > I think the same logic holds for adding untracked files > outside the sparsity cone. But it's actually even worse than that > case because there's a secondary level of surprise too: adding files > outside the sparsity cone will result in delayed user surprises when > the next git command that happens to call unpack_trees() (which are > found all over the codebase) removes the file from the working tree. > I've had some such reports already. I believe this is testing a realistic scenario that users are hitting in the wild today. I would believe that users succeed with these commands more often than they are confused by the file disappearing from the worktree in a later Git command, so having this sequence of events be documented as a potential use case has some value. I simultaneously don't think it is behavior we want to commit to as a contract for all future Git versions, but there is value in showing how this situation changes with any future meddling. In particular: will users be able to self-discover the "new" way of doing things? The proposal part of changing how add/mv/rm behave in these cases would need to adjust this test with something that would also help direct users to a helpful resolution. For example, the first run of git add sparse/dir/file could error out with an error message saying "The pathspec is outside of your sparse cone, so staging the file might lead to a staged change that is removed from your working directory." But we should _also_ include two strategies for getting out of this state: 1. Adjust your sparse-checkout definition so this file is in scope. -or- (and this is the part that would be new) 2. If you understand the risks of staging a file outside the sparse cone, then run 'git add --sparse sparse/dir/file'. (Insert whatever option would be appropriate for --sparse here.) Such a warning message would allow users who follow the steps listed in the test to know how to adjust their usage to then get into a good state. > If that test is marked as NEEDSWORK or even as the correct behavior > still being under dispute, then you can happily apply my: I would classify this as "The test documents current behavior, but isn't a contract for future behavior." With a concept such as my suggestion above, the test could be modified to check for the warning and then run the second command with the extra option and complete the test's expectations. Having the existing behavior documented in a test helps demonstrate how behavior is changing. We we've discussed, we want to give such a behavior change the right venue for feedback and suggestions for alternate approaches, and this series is not the right place for that. Hopefully you can tell that it is on my mind and that I want to recommend a change in the near future. Thanks, -Stolee
