From ac7e40cde23515da06683b2b0d4e61107bab8126 Mon Sep 17 00:00:00 2001
From: Vadim Zeitlin <vadim@wxwidgets.org>
Date: Thu, 20 Feb 2014 00:32:39 +0000
Subject: [PATCH] Don't use invalid pointer in file dialog hook procedure in
 wxMSW.

We can receive WM_NOTIFY for other than CDN_XXX messages if we have a native
control as our immediate child (which can happen with "extra" controls) and
the LPARAM is not a pointer to OFNOTIFY at all in this case, so don't try to
use it as such.

This fixes a crash when adding a "bare" extra control, see #16003.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@75941 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
---
 src/msw/filedlg.cpp | 32 ++++++++++++++++++--------------
 1 file changed, 18 insertions(+), 14 deletions(-)

diff --git a/src/msw/filedlg.cpp b/src/msw/filedlg.cpp
index 7327c7bdd7..15db452bae 100644
--- a/src/msw/filedlg.cpp
+++ b/src/msw/filedlg.cpp
@@ -172,22 +172,26 @@ wxFileDialogHookFunction(HWND      hDlg,
 
         case WM_NOTIFY:
             {
-                OFNOTIFY* const
-                    pNotifyCode = reinterpret_cast<OFNOTIFY *>(lParam);
-                wxFileDialog* const
-                    dialog = reinterpret_cast<wxFileDialog *>(
-                                    pNotifyCode->lpOFN->lCustData
-                                );
-
-                switch ( pNotifyCode->hdr.code )
+                NMHDR* const pNM = reinterpret_cast<NMHDR*>(lParam);
+                if ( pNM->code >= CDN_FIRST && pNM->code < CDN_LAST )
                 {
-                    case CDN_INITDONE:
-                        dialog->MSWOnInitDone((WXHWND)hDlg);
-                        break;
+                    OFNOTIFY* const
+                        pNotifyCode = reinterpret_cast<OFNOTIFY *>(lParam);
+                    wxFileDialog* const
+                        dialog = reinterpret_cast<wxFileDialog *>(
+                                        pNotifyCode->lpOFN->lCustData
+                                    );
 
-                    case CDN_SELCHANGE:
-                        dialog->MSWOnSelChange((WXHWND)hDlg);
-                        break;
+                    switch ( pNotifyCode->hdr.code )
+                    {
+                        case CDN_INITDONE:
+                            dialog->MSWOnInitDone((WXHWND)hDlg);
+                            break;
+
+                        case CDN_SELCHANGE:
+                            dialog->MSWOnSelChange((WXHWND)hDlg);
+                            break;
+                    }
                 }
             }
             break;