Fix handling returned $promise from async method, closes #1990

[jhthorsen]

Summary

Fix issue introduced in 166cedb when an async method returns a promise.

Motivation

@jberger reported the issue.

References

166cedb

[marcusramberg]

I think i understand what this fixes. Head slightly hurts now tho. 🍻 needed to remedy this situation.

[jberger]

Bad news, running my example from #1990 on this branch the example hangs.

perl -Ilib -Mojo -MMojo::Base=-async_await -E 'async sub main { print await doit() } async sub doit { await Mojo::Promise->timer(1); return Mojo::Promise->resolve("hello") } main()->wait'

[jhthorsen]

The (second) latest force push was pretty bad. I wonder if we can add this patch?

diff --git a/.github/workflows/linux.yml b/.github/workflows/linux.yml
index 1ced93691..ff9d404f6 100644
--- a/.github/workflows/linux.yml
+++ b/.github/workflows/linux.yml
@@ -30,9 +30,11 @@ jobs:
         run: |
           cpanm -n --installdeps .
           cpanm -n Cpanel::JSON::XS EV Role::Tiny
+          cpanm -n Future::AsyncAwait
           cpanm -n Test::Pod Test::Pod::Coverage
       - name: Run tests
         run: prove -l t t/mojo t/mojolicious
         env:
+          TEST_ASYNC_AWAIT: 1
           TEST_POD: 1
           TEST_EV: 1

@jberger: Either way, you can try again 👍

[jberger]

Yes, that fixes my example, thanks.

[jberger]

I also agree about that change to the github test runner, please open a PR for that too.

[marcusramberg]

third time is the charm, clearly ;-)