Gui: prevent native macOS color picker crash.

Fixes #25153

src/Gui/Widgets.cpp

@@ -749,8 +749,14 @@ void ColorButton::showModal()
             setColor(currentColor);
             Q_EMIT changed();
         }
+        setProperty("modal_dialog_active", false);
     });
 
+    /* A FocusOut event is sent when a native macOS color picker is opened, which
+     * closes the editor and destroys this object. Set a property to ignore this event.
+     */
+    setProperty("modal_dialog_active", true);
+
     dlg->exec();
 }
 

src/Gui/propertyeditor/PropertyItemDelegate.cpp

@@ -195,6 +195,12 @@ bool PropertyItemDelegate::eventFilter(QObject *o, QEvent *ev)
         }
     }
     else if (ev->type() == QEvent::FocusOut) {
+        if (auto button = qobject_cast<Gui::ColorButton*>(o)) {
+            // Ignore the event if the ColorButton's modal dialog is active.
+            if (button->property("modal_dialog_active").toBool()) {
+                return true;
+            }
+        }
         auto parentEditor = qobject_cast<PropertyEditor*>(this->parent());
         if (auto* comboBox = qobject_cast<QComboBox*>(o)) {
             if (parentEditor && parentEditor->activeEditor == comboBox) {