On Mon, Oct 30, 2023 at 10:33 PM Junio C Hamano <gitster@xxxxxxxxx> wrote: > > Junio C Hamano <gitster@xxxxxxxxx> writes: > > > Elijah Newren <newren@xxxxxxxxx> writes: > > > >> I thought the point of the comment_line_char was so that commit > >> messages could have lines starting with '#'. That rationale doesn't > >> apply to the TODO list generation or parsing, and I'm not sure if we > >> want to add the same complexity there. > > Earlier I said > > > Thanks for a healthy dose of sanity. I noticed existing use of > > comment_line_char everywhere in sequencer.c and assumed we would > > want to be consistent, but you are right to point out that they are > > all about the COMMIT_EDITMSG kind of thing, and not about what > > appears in "sequencer/todo". > > but with something as simple as > > $ git -c core.commentchar='@' rebase -i master seen^2 > > I can see that the references to comment_line_char in sequencer.c > are about the commented lines after the list of insn in the > generated sequencer/todo file, so even though the rationale does not > apply, isn't this already "broken" in the current code anyway? Yes, I believe it is. However, I remember specifically looking at cases with --rebase-merges about a year and a half ago, and noted that there was a mixture of hardcoded '#' references along with comment_line_char. I noted at the time that changing comment_line_char looked like it had a bug, and that the parsing in particular would be fooled and do wrong things if it changed. Unfortunately, I can't find any notes from the time with the details, so I don't remember exactly what or how it was triggered. However, I do suspect that the references to comment_line_char in the `rebase -i` codepaths was not for any actual intended purpose, but just noting that they were used elsewhere in the file (for COMMIT_EDITMSG, where it made sense) and just mimicking that code without realizing the lack of rationale. That would have been mere wasted effort had the comment_line_char been consistently supported in the TODO file editing and parsing, but it wasn't, which left TODO editing & parsing somewhat broken. I think supporting comment_line_char for the TODO file provides no value, and I think the easier fix would be undoing the uses of comment_line_char relative to the TODO file (perhaps also leaving in-code comments to the effect that comment_line_char just doesn't apply to the TODO file). However, if someone prefers to make the TODO file also respect comment_line_char, despite its dubious value, then I expect any patch should 1) audit *every* reference found via git grep -e '".*#' -e "'#'" sequencer.c 2) add a test case (or cases) involving --rebase-merges -i that trigger the relevant code paths If they don't do that, then I fear we might make the bug more likely to be triggered rather than less.
