Refs #1640. Unit test.

Tests/AppKit/CPEventTest.j

@@ -1,9 +1,16 @@
+@import <AppKit/CPApplication.j>
 @import <AppKit/CPEvent.j>
 
 @implementation CPEventTest : OJTestCase
 {
 }
 
+- (void)setUp
+{
+    // CPApplication must be initialised for some event handling to work.
+    [CPApplication sharedApplication];
+}
+
 /*!
     This test isn't very useful but it checks for any trouble related to issue #1202.
 */
@@ -16,4 +23,20 @@
     [self assert:0 equals:[anEvent deltaZ] message:"default event delta Z should be 0"];
 }
 
-@end
+- (void)testModifierFlags
+{
+    [self assert:0 equals:[CPEvent modifierFlags] message:@"no modifier flags active in a newly started app"];
+
+    var anEvent = [CPEvent keyEventWithType:CPKeyDown location:CGPointMakeZero() modifierFlags:CPShiftKeyMask timestamp:0 windowNumber:0 context:nil characters:"A" charactersIgnoringModifiers:"a" isARepeat:NO keyCode:0];
+    [CPApp sendEvent:anEvent];
+
+    [self assert:CPShiftKeyMask equals:[CPEvent modifierFlags] message:@"shift key pressed"];
+
+    // When the key up event is sent the modifier flags are cleared.
+    anEvent = [CPEvent keyEventWithType:CPKeyUp location:CGPointMakeZero() modifierFlags:0 timestamp:0 windowNumber:0 context:nil characters:"A" charactersIgnoringModifiers:"a" isARepeat:NO keyCode:0];
+    [CPApp sendEvent:anEvent];
+
+    [self assert:0 equals:[CPEvent modifierFlags] message:@"shift key released"];
+}
+
+@end