fix: EventLoop::post() deadlocks when posted function throws

Author: hulxv

src/mp/proxy.cpp

@@ -245,7 +245,9 @@ void EventLoop::loop()
         if (read_bytes != 1) throw std::logic_error("EventLoop wait_stream closed unexpectedly");
         Lock lock(m_mutex);
         if (m_post_fn) {
-            Unlock(lock, *m_post_fn);
+            KJ_IF_MAYBE(exception, kj::runCatchingExceptions([&]() { Unlock(lock, *m_post_fn); })) {
+                MP_LOG(*this, Log::Error) << "EventLoop: m_post_fn threw: " << kj::str(*exception).cStr();
+            }
             m_post_fn = nullptr;
             m_cv.notify_all();
         } else if (done()) {