On Wed, Sep 15 2021, Junio C Hamano wrote: [CC-ing Andreas Gruenbacher who's currently active in GNU patch development, and Paul Eggert at his current address, in case he's curious about this blast from the past. Both: The full context for this proposed change in Git is at https://lore.kernel.org/git/20210915223316.1653443-1-gitster@xxxxxxxxx/] > Long time ago, we had a discussion with GNU patch/diff maintainer > and agreed that pathnames with certain "difficult" bytes needs to be > quoted to ensure the resulting patch is machine parseable in an > unambiguous way [*1*]. Recently, we saw a report that found that > GNU patch is unhappy with our diff output for a path with SP in it > [*2*]. It would also be good to mention 4f6fbcdcf96 (Functions to quote and unquote pathnames in C-style., 2005-10-14) here, which is what came out of the [*1*] discussion you're citing, and that also link to the later: https://lore.kernel.org/git/7vll0wvb2a.fsf@xxxxxxxxxxxxxxxxxxxxxxxx/ Where you quote a message of Paul Eggert's that didn't make it into the archive, but which AFAICT accurately summarizes the behavior in 4f6fbcdcf96. Whereas the [*1*] you linked to is still the early proposal of handling UTF-8 specially (not quoting it), which doesn't appear to be what either GNU patch or Git went for in the end (both fully quote some fairly vanilla (also in latin1) UTF-8 when I tested it). It's still not clear to me if what was agreed upon was accurately implemented by Git at the time, but that GNU patch had a bug vis-a-vis the desired discussed behavior, if the bug is Git's, or both etc. Does a fix still need to be made in GNU patch? There's also a mention of busybox's interaction with this behavior in https://lore.kernel.org/git/YUK7Bl9uzNE1YErg@xxxxxxxxxx/; has anyone (you or Gwyneth) sent them an FYI about this in case they'd like to adjust the behavior of their patch tool? > Teach "git diff" and friends the "--quote-path-with-sp" option, that > encloses a pathname with SP in it inside a pair of double-quotes, > even though there is otherwise no byte in the pathname that need to > be encoded in the octal. > > As an earlier parts of t/t3902 (outside the patch context) shows, > output from "ls-files", "ls-tree", and "diff --name-only" all follow > the same rule to decide paths with what bytes in them need quoting > and how they are quoted. > > This experimental option deliberately refrains from touching these > output and affects ONLY the paths that appear in the patch header, > i.e. "diff --git", "--- a/path" and "+++ b/path" lines, that GNU > patch may care. This is to minimize potential damage this change > may cause to tools and scripts the users have been relying on. > > *1* https://lore.kernel.org/git/87ek6s0w34.fsf@xxxxxxxxxxxxxxxxxxx/ > *2* https://lore.kernel.org/git/YR9Iaj%2FFqAyCMade@xxxxxxxxxx/ > [...patch omitted...]
