[HttpClient] [EventSourceHttpClient] Fix consuming SSEs with \r\n separator

[fancyweb]

Q	A
Branch?	5.4
Bug fix?	yes
New feature?	no
Deprecations?	no
Issues	-
License	MIT

\r\n separator never worked because it splits on every line because of [\r\n].

[fancyweb]

There's another regex line 147 but I didn't modify it for safety (since we're on 5.4). It's untested, so its goal is unclear. Judging from the pattern, the intention might be to yield SSE comments (line starting with a colon) as DataChunk. If that's the case, then it's not working at all and it's another bug 😅

cc @nicolas-grekas @dunglas @soyuka since you worked on the initial implementation and you might remember something 🙏

[soyuka]

sure, when the line starts with a colon we need to skip see https://html.spec.whatwg.org/multipage/server-sent-events.html#event-stream-interpretation

[nicolas-grekas]

when the line starts with a colon we need to skip

yep, that's what we do on L147

[fancyweb]

yep, that's what we do on L147

It's not working as expected. I'll propose a patch, but on 7.1 because it's going to change the behavior heavily. Is that OK for you?

[nicolas-grekas]

on 7.1 because it's going to change the behavior heavily

Not sure: if we don't follow the spec, that's a bug and we need to fix it in 5.4.

[fancyweb]

We don't follow the spec but we've been yielding comments as SSE for more than 3 years 😅

[nicolas-grekas]

It doesn't matter, we don't want to preserve BC for a private buggy protocol :)

[fabpot]

Thank you @fancyweb.