Open Radar

 
Summary:

When a active (kCGEventTapOptionDefault) CGEventTap is created for kCGEventMouseMoved the "Hot Corners" Mission Control and the Dock hide/show features no longer work WHILE Finder is the active application (typically clicking on the desktop) AND the mouse movement is a slow one (really fast movements sometimes bypass this issue) 


Steps to Reproduce:

Compile and run a application with this code

CGEventRef tapCallBack(CGEventTapProxy proxy, CGEventType type, CGEventRef event, void* refcon)
{
    return event;
}    

CGEventMask mask = CGEventMaskBit(kCGEventMouseMoved);    
CFMachPortRef eventTap = CGEventTapCreate(kCGAnnotatedSessionEventTap, kCGHeadInsertEventTap, kCGEventTapOptionDefault, mask, tapCallBack, self);
CFRunLoopSourceRef runLoopSource = CFMachPortCreateRunLoopSource(kCFAllocatorDefault, eventTap, 0);
CFRunLoopAddSource([[NSRunLoop currentRunLoop] getCFRunLoop],runLoopSource, kCFRunLoopCommonModes);		
CGEventTapEnable(eventTap, true);
CFRelease(eventTap);		
CFRelease(runLoopSource);  

Click on desktop, move cursor to a corner to trigger a hot corner action or to the edge with the dock to show the dock. 

Expected Results:

The dock is shown/action is triggered.

Actual Results:

The dock is not shown/action is not triggered. 

Regression:

Moving the mouse/pointer pretty fast sometimes sidesteps the issue, also cycling/changing the active application either sidesteps or is a requisite for the issue to happen with no discern-able pattern.

Notes:

Example project attached.

changing kCGAnnotatedSessionEventTap to kCGSessionEventTap or kCGHIDEventTap fixes the bug