poll() blocks for ever when timeout is negative.

README.md

@@ -50,9 +50,9 @@ static pointer from_url(std::string url);
 static pointer create_dummy();
 
 // Function to perform actual network send()/recv() I/O:
-// (note: if all you need is to recv()/dispatch() messages, then timeout can be
-// used to block until a message arrives. By default, when timeout is 0, poll()
-// will not block at all.)
+// (note: if all you need is to recv()/dispatch() messages, then a
+// negative timeout can be used to block until a message arrives.
+// By default, when timeout is 0, poll() will not block at all.)
 void poll(int timeout = 0); // timeout in milliseconds
 
 // Receive a message, and pass it to callable(). Really, this just looks at

easywsclient.cpp

@@ -188,7 +188,7 @@ class _RealWebSocket : public easywsclient::WebSocket
             }
             return;
         }
-        if (timeout > 0) {
+        if (timeout != 0) {
             fd_set rfds;
             fd_set wfds;
             timeval tv = { timeout/1000, (timeout%1000) * 1000 };
@@ -196,7 +196,7 @@ class _RealWebSocket : public easywsclient::WebSocket
             FD_ZERO(&wfds);
             FD_SET(sockfd, &rfds);
             if (txbuf.size()) { FD_SET(sockfd, &wfds); }
-            select(sockfd + 1, &rfds, &wfds, NULL, &tv);
+            select(sockfd + 1, &rfds, &wfds, 0, timeout > 0 ? &tv : 0);
         }
         while (true) {
             // FD_ISSET(0, &rfds) will be true