From 1222ac3d7f80131f4f7a7b4e9994cf3c4a53af20 Mon Sep 17 00:00:00 2001
From: Xiaofeng Wang <1237906+wasphin@users.noreply.github.com>
Date: Sat, 7 Dec 2019 11:12:58 +0800
Subject: [PATCH] Fix crash in the splitter sample due to replacing null window

The sample could crash after the following sequence of actions:

1. Resize splitter to hide the right/left window.
2. Activate replace menu action.

Fix this by checking if the window being replaced is non-null.

Closes https://github.com/wxWidgets/wxWidgets/pull/1672
---
 samples/splitter/splitter.cpp | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/samples/splitter/splitter.cpp b/samples/splitter/splitter.cpp
index 523aa5d07a..6c6cd76f2b 100644
--- a/samples/splitter/splitter.cpp
+++ b/samples/splitter/splitter.cpp
@@ -448,8 +448,10 @@ void MyFrame::OnReplace(wxCommandEvent& WXUNUSED(event) )
 {
     if (m_replacewindow == NULL) {
         m_replacewindow = m_splitter->GetWindow2();
-        m_splitter->ReplaceWindow(m_replacewindow, new wxPanel(m_splitter, wxID_ANY));
-        m_replacewindow->Hide();
+        if (m_replacewindow != NULL) {
+            m_splitter->ReplaceWindow(m_replacewindow, new wxPanel(m_splitter, wxID_ANY));
+            m_replacewindow->Hide();
+        }
     } else {
         wxWindow *empty = m_splitter->GetWindow2();
         wxASSERT(empty != m_replacewindow);