Crash in SIApplication.m in observerCallback

[ianfixes]

System

• Amethyst version: 0.11.4 (52)
• macOS version: 10.12.6

What's the problem?

This crash happens infrequently, but always in the same place. I suspect a race condition while closing a window, which creates a null pointer that the observerCallback is not handling.

void observerCallback(AXObserverRef observer, AXUIElementRef element, CFStringRef notification, void *refcon) {
    SIAXNotificationHandler callback = (__bridge SIAXNotificationHandler)refcon;
    SIWindow *window = [[SIWindow alloc] initWithAXElement:element];
    callback(window);
}

(lldb) po window
<c0d06200 80610000 00000000 00000000>

(lldb) po observer
<AXObserver 0x61800089d0b0> {pid=52339}

(lldb) po element
<AXUIElement 0x60002b645c40> {pid=52339}

(lldb) po notification
AXUIElementDestroyed

(lldb) po refcon
<AXUIElement 0x60002b45e330> {pid=52339}

(lldb) po callback 
0x0000000000000010

(lldb) 

How can it be reproduced?

No idea. It happens once every 3+ weeks.

What applications are involved?

Not application specific, as far as I can tell.

Has anything fixed it, even temporarily?

Luck.

[ianfixes]

Oops, of course I'm not going to find the open issue when I'm looking in Amethyst instead of Silica.

This belongs here: ianyh/Silica#10