include asset again into error pages

[eschultz-magix]

Symfony version(s) affected: 4.2

Description
The EntrypointLookup prevents including a file multiple times by default. But it prevents re-using a stylesheet in an error template if an error occurs during the rendering of a template that re-uses the layout. This is because the ExceptionController will clear the output buffers.

How to reproduce

1. checkout symfony/demo
2. add a twig runtime error into the homepage template inside the body, f.ex. {{ 1 / 0 }}
3. the error template will not embed the "css/app" stylesheet again as it has been already rendered before

Possible Solution
The EntryPointLookup class must only return a template once per request.

[weaverryan]

Hey!

Thanks for confirming this - we have a PR for this #21 - we just need to finish it. I think the approach is that we should always call reset when an exception is thrown (via a listener).

[carsonbot]

Thank you for this issue.
There has not been a lot of activity here for a while. Has this been resolved?

[carsonbot]

Just a quick reminder to make a comment on this. If I don't hear anything I'll close this.

[MrMitch]

Seeing that #24 is closed in favor of #71 which has been merged, I think this could be closed as well ?

@eschultz-magix @weaverryan what do you think ?