1 files changed, 38 insertions, 33 deletions
diff --git a/src/library_browser.js b/src/library_browser.js
index 4be7315e..44e8c473 100644
--- a/src/library_browser.js
+++ b/src/library_browser.js
@@ -196,41 +196,42 @@ mergeInto(LibraryManager.library, {
       // Canvas event setup
 
       var canvas = Module['canvas'];
-      
-      // forced aspect ratio can be enabled by defining 'forcedAspectRatio' on Module
-      // Module['forcedAspectRatio'] = 4 / 3;
-      
-      canvas.requestPointerLock = canvas['requestPointerLock'] ||
-                                  canvas['mozRequestPointerLock'] ||
-                                  canvas['webkitRequestPointerLock'] ||
-                                  canvas['msRequestPointerLock'] ||
-                                  function(){};
-      canvas.exitPointerLock = document['exitPointerLock'] ||
-                               document['mozExitPointerLock'] ||
-                               document['webkitExitPointerLock'] ||
-                               document['msExitPointerLock'] ||
-                               function(){}; // no-op if function does not exist
-      canvas.exitPointerLock = canvas.exitPointerLock.bind(document);
-
-      function pointerLockChange() {
-        Browser.pointerLock = document['pointerLockElement'] === canvas ||
-                              document['mozPointerLockElement'] === canvas ||
-                              document['webkitPointerLockElement'] === canvas ||
-                              document['msPointerLockElement'] === canvas;
-      }
+      if (canvas) {
+        // forced aspect ratio can be enabled by defining 'forcedAspectRatio' on Module
+        // Module['forcedAspectRatio'] = 4 / 3;
+        
+        canvas.requestPointerLock = canvas['requestPointerLock'] ||
+                                    canvas['mozRequestPointerLock'] ||
+                                    canvas['webkitRequestPointerLock'] ||
+                                    canvas['msRequestPointerLock'] ||
+                                    function(){};
+        canvas.exitPointerLock = document['exitPointerLock'] ||
+                                 document['mozExitPointerLock'] ||
+                                 document['webkitExitPointerLock'] ||
+                                 document['msExitPointerLock'] ||
+                                 function(){}; // no-op if function does not exist
+        canvas.exitPointerLock = canvas.exitPointerLock.bind(document);
+
+        function pointerLockChange() {
+          Browser.pointerLock = document['pointerLockElement'] === canvas ||
+                                document['mozPointerLockElement'] === canvas ||
+                                document['webkitPointerLockElement'] === canvas ||
+                                document['msPointerLockElement'] === canvas;
+        }
 
-      document.addEventListener('pointerlockchange', pointerLockChange, false);
-      document.addEventListener('mozpointerlockchange', pointerLockChange, false);
-      document.addEventListener('webkitpointerlockchange', pointerLockChange, false);
-      document.addEventListener('mspointerlockchange', pointerLockChange, false);
+        document.addEventListener('pointerlockchange', pointerLockChange, false);
+        document.addEventListener('mozpointerlockchange', pointerLockChange, false);
+        document.addEventListener('webkitpointerlockchange', pointerLockChange, false);
+        document.addEventListener('mspointerlockchange', pointerLockChange, false);
 
-      if (Module['elementPointerLock']) {
-        canvas.addEventListener("click", function(ev) {
-          if (!Browser.pointerLock && canvas.requestPointerLock) {
-            canvas.requestPointerLock();
-            ev.preventDefault();
-          }
-        }, false);
+        if (Module['elementPointerLock']) {
+          canvas.addEventListener("click", function(ev) {
+            if (!Browser.pointerLock && canvas.requestPointerLock) {
+              canvas.requestPointerLock();
+              ev.preventDefault();
+            }
+          }, false);
+        }
       }
     },
 
@@ -429,11 +430,13 @@ mergeInto(LibraryManager.library, {
       });
     },
     safeSetTimeout: function(func, timeout) {
+      Module['noExitRuntime'] = true;
       return setTimeout(function() {
         if (!ABORT) func();
       }, timeout);
     },
     safeSetInterval: function(func, timeout) {
+      Module['noExitRuntime'] = true;
       return setInterval(function() {
         if (!ABORT) func();
       }, timeout);
@@ -886,6 +889,8 @@ mergeInto(LibraryManager.library, {
   emscripten_set_main_loop: function(func, fps, simulateInfiniteLoop, arg) {
     Module['noExitRuntime'] = true;
 
+    assert(!Browser.mainLoop.scheduler, 'there can only be one main loop function at once: call emscripten_cancel_main_loop to cancel the previous one, if you want to');
+
     Browser.mainLoop.runner = function Browser_mainLoop_runner() {
       if (ABORT) return;
       if (Browser.mainLoop.queue.length > 0) {