EMSCRIPTEN: HTTP requests are not working

[mgerhardy]

ERROR: Http request for 'https://api.github.com/repos/vengi-voxel/vengi/releases/latest' failed [vengi-voxedit.js:1:26304](https://vengi-voxel.de/ve/vengi-voxedit.js)
    put_char https://vengi-voxel.de/ve/vengi-voxedit.js:1
    write https://vengi-voxel.de/ve/vengi-voxedit.js:1
    write https://vengi-voxel.de/ve/vengi-voxedit.js:1
    doWritev https://vengi-voxel.de/ve/vengi-voxedit.js:1
    _fd_write https://vengi-voxel.de/ve/vengi-voxedit.js:1
    <anonymous> https://vengi-voxel.de/ve/vengi-voxedit.wasm:5479493
    <anonymous> https://vengi-voxel.de/ve/vengi-voxedit.wasm:2012463
    <anonymous> https://vengi-voxel.de/ve/vengi-voxedit.wasm:2012205
    <anonymous> https://vengi-voxel.de/ve/vengi-voxedit.wasm:513390
    <anonymous> https://vengi-voxel.de/ve/vengi-voxedit.wasm:5692858
    <anonymous> https://vengi-voxel.de/ve/vengi-voxedit.wasm:2902217
    <anonymous> https://vengi-voxel.de/ve/vengi-voxedit.wasm:7337316
    <anonymous> https://vengi-voxel.de/ve/vengi-voxedit.wasm:5822079
    <anonymous> https://vengi-voxel.de/ve/vengi-voxedit.wasm:766820
    <anonymous> https://vengi-voxel.de/ve/vengi-voxedit.wasm:21433
    <anonymous> https://vengi-voxel.de/ve/vengi-voxedit.wasm:848762
    <anonymous> https://vengi-voxel.de/ve/vengi-voxedit.wasm:5190101
    <anonymous> https://vengi-voxel.de/ve/vengi-voxedit.wasm:7201103
    <anonymous> https://vengi-voxel.de/ve/vengi-voxedit.wasm:7203795
    callUserCallback https://vengi-voxel.de/ve/vengi-voxedit.js:1
    runIter https://vengi-voxel.de/ve/vengi-voxedit.js:1
    Browser_mainLoop_runner https://vengi-voxel.de/ve/vengi-voxedit.js:1
    (Async: FrameRequestCallback)
    requestAnimationFrame https://vengi-voxel.de/ve/vengi-voxedit.js:1
    Browser_mainLoop_scheduler_rAF https://vengi-voxel.de/ve/vengi-voxedit.js:1
    Browser_mainLoop_runner https://vengi-voxel.de/ve/vengi-voxedit.js:1
    (Async: FrameRequestCallback)

The latest emscripten removed the support for synchronous downloads from the main thread. See emscripten-core/emscripten#8070 for more details behind the reasoning.

We've adopted our code in that regards in 0a1daa9 - but this is of course not an ideal solution as the unittests can run, and not all parts are downloaded from threads. We most likely should refactor the Request class to return a future or some kind of state that you can query to implement fully async downloads for all drivers (winhttp, curl and emscripten)

• https://github.com/emscripten-core/emscripten/blob/1171adaa21048ba8dc82169b9d79952e8754b201/system/lib/fetch/emscripten_fetch.c#L149
• https://github.com/emscripten-core/emscripten/blob/1171adaa21048ba8dc82169b9d79952e8754b201/system/lib/fetch/emscripten_fetch.c#L81

[mgerhardy]

0a1daa9 - not yet working - only works from threads in sync mode - see emscripten-core/emscripten#8070