Merge branch 'incoming'

1 files changed, 14 insertions, 5 deletions

diff --git a/src/library_browser.js b/src/library_browser.js
index 8444fb73..b368c6ac 100644
--- a/src/library_browser.js
+++ b/src/library_browser.js
@@ -250,15 +250,24 @@ mergeInto(LibraryManager.library, {
           contextAttributes.preserveDrawingBuffer = true;
 #endif
 
-          ['experimental-webgl', 'webgl'].some(function(webglId) {
-            return ctx = canvas.getContext(webglId, contextAttributes);
-          });
+          var errorInfo = '?';
+          function onContextCreationError(event) {
+            errorInfo = event.statusMessage || errorInfo;
+          }
+          canvas.addEventListener('webglcontextcreationerror', onContextCreationError, false);
+          try {
+            ['experimental-webgl', 'webgl'].some(function(webglId) {
+              return ctx = canvas.getContext(webglId, contextAttributes);
+            });
+          } finally {
+            canvas.removeEventListener('webglcontextcreationerror', onContextCreationError, false);
+          }
         } else {
           ctx = canvas.getContext('2d');
         }
         if (!ctx) throw ':(';
       } catch (e) {
-        Module.print('Could not create canvas - ' + e);
+        Module.print('Could not create canvas: ' + [errorInfo, e]);
         return null;
       }
       if (useWebGL) {
@@ -854,7 +863,7 @@ mergeInto(LibraryManager.library, {
     var styleSheet = document.styleSheets[0];
     var rules = styleSheet.cssRules;
     for (var i = 0; i < rules.length; i++) {
-      if (rules[i].cssText.substr(0, 5) == 'canvas') {
+      if (rules[i].cssText.substr(0, 6) == 'canvas') {
         styleSheet.deleteRule(i);
         i--;
       }