From 35a4f486803d3a707844517d2338a93b286c8a5f Mon Sep 17 00:00:00 2001
From: Fatih Uzunoglu <fuzun54@outlook.com>
Date: Tue, 29 Mar 2022 17:14:28 +0300
Subject: [PATCH] qt: don't allow PrefsDialog to open multiple times in
 DialogsProvider

allowing PrefsDialog to be opened multiple time causes massive freezing
---
 modules/gui/qt/dialogs/dialogs_provider.cpp | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/modules/gui/qt/dialogs/dialogs_provider.cpp b/modules/gui/qt/dialogs/dialogs_provider.cpp
index eaa5448908..2bc1efc649 100644
--- a/modules/gui/qt/dialogs/dialogs_provider.cpp
+++ b/modules/gui/qt/dialogs/dialogs_provider.cpp
@@ -62,6 +62,7 @@
 #include <QFileDialog>
 #include <QUrl>
 #include <QInputDialog>
+#include <QPointer>
 
 #define I_OP_DIR_WINTITLE I_DIR_OR_FOLDER( N_("Open Directory"), \
                                            N_("Open Folder") )
@@ -248,9 +249,18 @@ const QEvent::Type DialogEvent::DialogEvent_Type =
 
 void DialogsProvider::prefsDialog()
 {
-    PrefsDialog *p = new PrefsDialog( nullptr, p_intf );
-    p->setAttribute(Qt::WA_DeleteOnClose);
-    p->toggleVisible();
+    static QPointer<PrefsDialog> p;
+
+    if (Q_LIKELY(!p))
+    {
+        p = new PrefsDialog( nullptr, p_intf );
+        p->setAttribute(Qt::WA_DeleteOnClose);
+        p->open();
+    }
+    else
+    {
+        p->reject();
+    }
 }
 
 void DialogsProvider::firstRunDialog()