Merge pull request #375 from mitchellh/macos-free

macos: break reference cycle to window to allow window to free memory

macos/Sources/Features/Primary Window/PrimaryWindowController.swift

@@ -11,4 +11,14 @@ class PrimaryWindowController: NSWindowController {
         guard let manager = self.windowManager else { return }
         manager.triggerNewTab(for: window)
     }
+    
+    deinit {
+        // I don't know if this is the right place, but because of WindowAccessor in our
+        // SwiftUI hierarchy, we have a reference cycle between view and window and windows
+        // are never freed. When the window is closed, the window controller is deinitialized,
+        // so we can use this opportunity detach the view from the window and break the cycle.
+        if let window = self.window {
+            window.contentView = nil
+        }
+    }
 }