Stash workdir correctly when added in the index, modified in the workdir #3250
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Drop `git_diff__merge_like_cgit_reversed`, since it's a copy and paste mess of slightly incompatible changes.
Ensure that when a file is added in the index and subsequently modified in the working directory, the stashed working directory tree contains the actual working directory contents.
When stashing the workdir tree, examine the index as well. Using a mechanism similar to `git_diff_tree_to_workdir_with_index` allows us to determine that a file was added in the index and subsequently modified in the working directory. Without examining the index, we would erroneously believe that this file was untracked and fail to include it in the working directory tree. Use a slightly modified `git_diff_tree_to_workdir_with_index` in order to avoid some of the behavior custom to `git diff`. In particular, be sure to include the working directory side of a file when it was deleted in the index.
| const git_diff_delta *left = reversed ? f : o; | ||
| const git_diff_delta *right = reversed ? o : f; | ||
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| delta = cb(left, right, &onto_pool); |
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So when I was working on this code, I wondered myself why diff_delta__merge_like_cgit_reversed() even existed vs just swapping the parameters to diff_delta__merge_like_cgit().
If you look at the implementation of diff_delta__merge_like_cgit_reversed(), it's actually not exactly the "reverse" of diff_delta__merge_like_cgit IIRC. Are you sure this is safe?
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Indeed. It looks like there are a handful of changes to each since they were written. I tried to make sure that the unique changes to each were reflected in the new function. Was there something in particular that you're concerned about?
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Nothing in particular as I don't remember right now the past edge cases I had to deal when using this merge API. I do remember I spent a lot of time dealing with its peculiarities though. Anyway, looks like you have this covered already!
Stash workdir correctly when added in the index, modified in the workdir
We do not presently stash files correctly when a file is added in the index and then modified in the working directory. We are examining only the working directory with regard to the HEAD, and without examining the index as well (with that file staged) we treat that file as untracked and thus do not include it in the workdir tree.
Correct that by using a diff that includes the index similar to
git_diff_tree_to_workdir_with_indexbut with different special cases. (git_diff_tree_to_workdir_with_indexis aimed at producing something likegit diffand so collapses some cases - we differ in that we want to ensure that we still pay attention to the workdir side when the index side is deleted.)