From 5dbc87caf0b4e6ea548baa7972dea766786201cb Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Fri, 13 Nov 2020 19:09:30 -0500
Subject: [PATCH] Smarter: just ensures any attached panels are closed at
 close().

---
 .../Documents/MachineDocument.swift           | 20 ++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/OSBindings/Mac/Clock Signal/Documents/MachineDocument.swift b/OSBindings/Mac/Clock Signal/Documents/MachineDocument.swift
index 2337a84af..47d423d40 100644
--- a/OSBindings/Mac/Clock Signal/Documents/MachineDocument.swift	
+++ b/OSBindings/Mac/Clock Signal/Documents/MachineDocument.swift	
@@ -88,14 +88,30 @@ class MachineDocument:
 	}
 
 	override func close() {
+		// Close any dangling sheets.
+		//
+		// Be warned: in 11.0 at least, if there are any panels then posting the endSheet request
+		// will defer the close(), and close() will be called again at the end of that animation.
+		//
+		// So: MAKE SURE IT'S SAFE TO ENTER THIS FUNCTION TWICE. Hence the non-assumption here about
+		// any windows still existing.
+		if self.windowControllers.count > 0, let window = self.windowControllers[0].window {
+			for sheet in window.sheets {
+				window.endSheet(sheet)
+			}
+		}
+
+		// Stop the machine, if any.
 		machine?.stop()
 
+		// Dismiss panels.
 		activityPanel?.setIsVisible(false)
 		activityPanel = nil
 
 		optionsPanel?.setIsVisible(false)
 		optionsPanel = nil
 
+		// End the update cycle.
 		actionLock.lock()
 		drawLock.lock()
 		machine = nil
@@ -103,6 +119,7 @@ class MachineDocument:
 		actionLock.unlock()
 		drawLock.unlock()
 
+		// Let the document controller do its thing.
 		super.close()
 	}
 
@@ -364,8 +381,6 @@ class MachineDocument:
 	}
 
 	@IBAction func cancelCreateMachine(_ sender: NSButton?) {
-		self.windowControllers[0].window?.endSheet(self.machinePickerPanel!)
-		self.machinePicker = nil
 		close()
 	}
 
@@ -395,7 +410,6 @@ class MachineDocument:
 	}
 
 	@IBAction func cancelRequestROMs(_ sender: NSButton?) {
-		self.windowControllers[0].window?.endSheet(self.romRequesterPanel!)
 		close()
 	}