Re: [BUG] stash.index=true leaves a redundant stash entry after an autostash fast-forward

[Phillip Wood <phillip.wood123@gmail.com>]

Hi Ben

On 16/09/2026 15:30, Ben Knoble wrote:
>> Le 16 sept. 2026 à 09:35, Phillip Wood <phillip.wood123@gmail.com> a écrit :
>> Taking a step back, this code applies the stashed index changes
>> into the current index, writes the result to a tree and then resets
>> the index to HEAD. We could avoid touching the index at all if we
>> used merge_incore_nonrecursive() to cherry pick the index changes
>> instead. That way we'd get a proper three-way merge and avoid
>> spawning subprocesses for "git diff-tree", "git apply --cached",
>> and "git reset". We're already using merge_ort_nonrecursive() to
>> merge the working tree changes in that function so we have nearly
>> everything we need already set up to merge the index changes as
>> well. Essentially, when merging the index, we just need to call
>> merge_incore_nonrecursive() instead of merge_ort_nonrecursive()
>> and use info->i_tree instead of info->w_tree.

> 
> Wow, I wish I’d had this info this morning! I spent a couple hours
 > trying to understand this flow and still don’t have it in my head :)
 > Thanks for the pointers.
It is a bit confusing the way it updates the index, then resets it only 
to update it again at the end. I don't think we can avoid that though if 
we want to error out when there are conflicts merging the index.

> I may try to summarize my own notes (= questions about the existing
 > code) and send those out later today, though, since I’d love to make
 > my understanding line up with yours!
I'm happy to try and answer any questions, on or off the list - it would 
be really nice if we can merge the index changes and avoid a bunch a 
subprocesses.

Thanks

Phillip