Re: [PATCH 0/3] Fix stash apply in sparse checkouts (and a submodule test)

"Elijah Newren via GitGitGadget" [off-list ref] writes:

Heavier usage of sparse-checkouts at $DAYJOB is commencing. And an issue
with git stash apply was found.

git stash's implementation as a pipeline of forked commands presents some
problems, especially when implemented atop of three commands that all behave
differently in the presence of sparse checkouts. Add a testcase
demonstrating some issues with git stash apply in a repository with a
different set of sparse-checkout patterns at apply vs create time, clean up
the relevant section of git stash code, and incidentally fix a submodule
testcase unrelated to sparse checkouts. Provide some detailed commit
messages explaining the issues along the way.

NOTE: I found a couple minor issues with other commands in sparse checkouts
while debugging this issue, but I don't yet have fixes for them and I can
submit them separately.

Any comments on this from reviewers?  The second patch is a but too
busy looking and I am having a bit of trouble convincing myself that
it is doing the right thing.

Thanks.