Git: my git stash -p optimization in Git 2.55

I got another commit merged in Git 2.55 (2026-06-29), yay! The release note reads: "git stash -p" has been optimized by reusing cached index entries in its temporary index, avoiding unnecessary lstat() calls on unchanged files. Here is the story of this change. Patch mode slowness The -p (--patch) option makes git stash interactive. Instead of stashing everything, Git walks you through your uncommitted changes hunk by hunk, asking whether to stash each one, using the same interactive machinery as git add -p. (I covered this option, and many more tips, in my book Boost Your Git DX.) I love using git stash -p to store parts of my changes, such as to leave unrelated edits for committing later on another branch, or to temporarily remove a bug fix to check that my new tests fail without it. But I found the command was slow in my client Rippling’s monorepo, taking about 35 seconds to even show the first prompt. Every time I ran it, I sat there in frustration, or cancelled it and used the…