Merge branch 'rikuayanokozy-fix-filedrophandler'

Author: joeltine

closure/goog/events/filedrophandler.js

@@ -196,7 +196,14 @@ goog.events.FileDropHandler.prototype.onElemDragOver_ = function(e) {
     e.stopPropagation();
     // Allow the drop on the drop zone.
     var dt = e.getBrowserEvent().dataTransfer;
-    dt.effectAllowed = 'all';
+
+    // IE bug #811625 (https://goo.gl/UWuxX0) will throw error SCRIPT65535
+    // when attempting to set property effectAllowed on IE10+.
+    // See more: https://github.com/google/closure-library/issues/485.
+    try {
+      dt.effectAllowed = 'all';
+    } catch (e) {
+    }
     dt.dropEffect = 'copy';
   }
 };

closure/goog/events/filedrophandler_test.js

@@ -248,3 +248,32 @@ function testPreventDropOutside() {
   // Assert also that the drop effect is set to 'none'.
   assertEquals('none', dt.dropEffect);
 }
+
+function testEffectAllowedExceptionIsCaught() {
+  var preventDefault = false;
+  var expectedfiles = [{fileName: 'file1.jpg'}];
+  var dt = {types: ['Files'], files: expectedfiles};
+
+  // We construct a mock DataTransfer object that define a setter will throw
+  // SCRIPT65535 when attempt to set property effectAllowed to simulate IE Bug
+  // #811625. See more: https://github.com/google/closure-library/issues/485.
+  Object.defineProperty(dt, 'effectAllowed',
+                        {set: function(v) { throw new Error("SCRIPT65535"); }});
+
+  // Assert that default actions are prevented on dragenter.
+  textarea.dispatchEvent(new goog.events.BrowserEvent({
+    preventDefault: function() { preventDefault = true; },
+    type: goog.events.EventType.DRAGENTER,
+    dataTransfer: dt
+  }));
+  assertTrue(preventDefault);
+  preventDefault = false;
+
+  // Assert that default actions are prevented on dragover.
+  textarea.dispatchEvent(new goog.events.BrowserEvent({
+    preventDefault: function() { preventDefault = true; },
+    type: goog.events.EventType.DRAGOVER,
+    dataTransfer: dt
+  }));
+  assertTrue(preventDefault);
+}