From: Johannes Schindelin Date: Wed, 24 Sep 2025 11:19:32 GMT Subject: Re: [PATCH v4 3/3] diff --no-index: support limiting by pathspec Message-ID: <35e55d20-d4aa-4b88-aa93-9192612fd1b8@gmx.de> In-Reply-To: Hi Jacob, On Tue, 23 Sep 2025, Jacob Keller wrote: > On 9/23/2025 7:57 AM, Johannes Schindelin wrote: > > > However, this makes me wonder whether the logic itself is sound? It is > > not immediately obvious to me why the `paths[0]` and `paths[1]` values > > aren't matched against the pathspec yet their entirety is seemingly > > skipped in `read_directory_contents()`? > > I recall fiddling a lot to try and get this working. The idea here is > that fixup_paths does some conversions to handle the DWIM logic where a > "diff D F" becomes "diff D/F F". It returns true if both paths are > directories, so we only enter this block when both paths are > directories. (Which is required because we only support pathspec > limiting for directory differences). I do wonder, after seeing that `read_directory_contents()` has to (re-)construct a complete `strbuf` in every single invocation whether it would make more sense to construct two `strbuf`s in `diff_no_index()` and pass those along to `queue_diff()` _instead_ of `skip1`/`skip2`. The `queue_diff()` function would then have to extend these `strbuf`s as it already does with `buffer1`/`buffer2`. That would avoid appending the same prefix only to remove it right away (with a not exactly cheap `memmove()`) during every `read_directory_contents()` invocation, too, in addition to allocating and releasing those `strbuf`s over and over again. Ciao, Johannes