`emscripten_clear_timeout` fails to clear/pop the keepalive counter.

[sbc100]

emscripten_set_timeout increases the keepalive count but emscripten_clear_timeout doesn't decrease it.

This mean that programs that call emscripten_clear_timeout will incorrectly stay alive longer than they expect.

[stevenwdv]

I also experienced this issue, but ended up just using the Web API directly.

Note that clearTimeout is a no-op for unknown IDs, including already expired timeouts, in which case you don't want to decrease the keepalive count. However, i.m.o. you shouldn't be calling clearTimeout with an ID for which you aren't sure if it (still) exists, since browsers are allowed to reuse expired IDs, so you could end up canceling a different timer. This does mean that using this Web API in a robust way is not as straightforward as you might think.

If you want to see the code I ended up using, you can find it here.

[sbc100]

@guybedford, looks like we have an issue here that you can close with #27720 ?