Re: [PATCH] userdiff: support Markdown

["Ash Holland" <ash@sorrel.sh>]

On Fri Apr 24, 2020 at 8:21 PM BST, Johannes Sixt wrote:
> Am 24.04.20 um 01:42 schrieb Ash Holland:
> > On Thu Apr 23, 2020 at 9:17 PM PST, Johannes Sixt wrote:
> >> Am 21.04.20 um 03:00 schrieb Ash Holland:
> >>> diff --git a/userdiff.c b/userdiff.c
> >>> index efbe05e5a..f79adb3a3 100644
> >>> --- a/userdiff.c
> >>> +++ b/userdiff.c
> >>> @@ -79,6 +79,9 @@ PATTERNS("java",
> >>>  	 "|[-+0-9.e]+[fFlL]?|0[xXbB]?[0-9a-fA-F]+[lL]?"
> >>>  	 "|[-+*/<>%&^|=!]="
> >>>  	 "|--|\\+\\+|<<=?|>>>?=?|&&|\\|\\|"),
> >>> +PATTERNS("markdown",
> >>> +	 "^ {0,3}#{1,6}( .*)?$",
> >>
> >> What is the purpose of making the heading text optional? Why would you
> >> want to match a sequence of hash marks without any text following it?
> > 
> > Strictly speaking, a markdown heading is allowed to be empty -- see for
> > example https://spec.commonmark.org/0.29/#example-49. I'm happy to
> > change it if you think it's more useful to show a previous heading which
> > contains text than an empty one, though.
>
> I don't know what makes sense, I don't write markdown regularly. A quick
> check shows that the sequence of hashmarks appears in the hunk header.
> Is that useful? (A genuine question!)

I think probably it would be more confusing to have Git silently ignore
empty headings, having occasionally written documents with empty
headings in the past (e.g. when I know I want some different sections,
but I don't know what to call them yet). Probably not many people would
ever run into this situation either way, though.