From 6ee518417137651e4a46959eb1a86fda6dc93155 Mon Sep 17 00:00:00 2001
From: Vadim Zeitlin <vadim@wxwidgets.org>
Date: Wed, 26 Jun 2019 18:37:31 +0200
Subject: [PATCH] Check window validity in wxNonOwnedWindow::Update() in wxMac
 too

This was already done in the other functions, but not this one,
resulting in a crash if it was called for an object with null m_nowpeer
(e.g. before it's created or when it's not a real wxNonOwnedWindow
object as when it's a subobject of wxTDIChildFrame).

See #18423.
---
 src/osx/nonownedwnd_osx.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/osx/nonownedwnd_osx.cpp b/src/osx/nonownedwnd_osx.cpp
index cbc20eda73..d17624f029 100644
--- a/src/osx/nonownedwnd_osx.cpp
+++ b/src/osx/nonownedwnd_osx.cpp
@@ -481,6 +481,9 @@ void wxNonOwnedWindow::WindowWasPainted()
 
 void wxNonOwnedWindow::Update()
 {
+    if ( m_nowpeer == NULL )
+        return;
+
     if ( clock() - s_lastFlush > CLOCKS_PER_SEC / 30 )
     {
         s_lastFlush = clock();