From da46ee6c7ab696c9c3eb8bf80cb612e7d254d743 Mon Sep 17 00:00:00 2001
From: reuk <reuk@users.noreply.github.com>
Date: Thu, 18 Nov 2021 19:34:20 +0000
Subject: [PATCH] FileChooser:  Launch chooser asynchronously

When FileChooser instances were created, launched, and hidden all inside
the same event callback on macOS 12.0.1, the chooser dialog sometimes
remained open. This could cause problems including crashes, as closing
the dialog would attempt to call a completion handler block referencing
an already-deleted FileChooser::Native instance.

Opening the chooser panel later on the message thread seems to resolve
the issue.
---
 .../native/juce_mac_FileChooser.mm            | 24 +++++++++----------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/modules/juce_gui_basics/native/juce_mac_FileChooser.mm b/modules/juce_gui_basics/native/juce_mac_FileChooser.mm
index 3cf1337cad..c3565d557b 100644
--- a/modules/juce_gui_basics/native/juce_mac_FileChooser.mm
+++ b/modules/juce_gui_basics/native/juce_mac_FileChooser.mm
@@ -82,8 +82,9 @@ public:
         filters.trim();
         filters.removeEmptyStrings();
 
-        NSString* nsTitle = juceStringToNS (owner.title);
+        auto* nsTitle = juceStringToNS (owner.title);
         [panel setTitle: nsTitle];
+        [panel setReleasedWhenClosed: YES];
 
         JUCE_BEGIN_IGNORE_WARNINGS_GCC_LIKE ("-Wdeprecated-declarations")
         [panel setAllowedFileTypes: createAllowedTypesArray (filters)];
@@ -153,22 +154,14 @@ public:
             if (nsViewPreview != nil)
             {
                 [panel setAccessoryView: nil];
-
                 [nsViewPreview release];
-
-                nsViewPreview = nil;
-                preview = nullptr;
             }
 
             [panel close];
-            [panel release];
         }
 
         if (delegate != nil)
-        {
             [delegate release];
-            delegate = nil;
-        }
     }
 
     void launch() override
@@ -179,10 +172,17 @@ public:
             addToDesktop (0);
 
             enterModalState (true);
-            [panel beginWithCompletionHandler:CreateObjCBlock (this, &Native::finished)];
 
-            if (preview != nullptr)
-                preview->toFront (true);
+            MessageManager::callAsync ([ref = SafePointer<Native> (this)]
+            {
+                if (ref == nullptr)
+                    return;
+
+                [ref->panel beginWithCompletionHandler: CreateObjCBlock (ref.getComponent(), &Native::finished)];
+
+                if (ref->preview != nullptr)
+                    ref->preview->toFront (true);
+            });
         }
     }