fix m_sizerPage memory leak for the wizards not using sizers (replaces patch 1708331, fixes bug 1647290) [backport from HEAD]

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_8_BRANCH@45723 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

docs/changes.txt

@@ -105,6 +105,7 @@ All (Unix):
 All (GUI):
 
 - Allow status bar children in XRC (Edmunt Pienkowski)
+- Fix memory leak in wxWizard when not using sizers for the page layout
 
 wxMSW:
 

include/wx/generic/wizard.h

@@ -45,6 +45,10 @@ public:
              long style = wxDEFAULT_DIALOG_STYLE);
     void Init();
 
+#if wxABI_VERSION >= 20804
+    virtual ~wxWizard();
+#endif
+
     // implement base class pure virtuals
     virtual bool RunWizard(wxWizardPage *firstPage);
     virtual wxWizardPage *GetCurrentPage() const;

src/generic/wizard.cpp

@@ -326,6 +326,15 @@ bool wxWizard::Create(wxWindow *parent,
     return result;
 }
 
+wxWizard::~wxWizard()
+{
+    // normally we don't have to delete this sizer as it's deleted by the
+    // associated window but if we never used it or didn't set it as the window
+    // sizer yet, do delete it manually
+    if ( !m_usingSizer || !m_started )
+        delete m_sizerPage;
+}
+
 void wxWizard::AddBitmapRow(wxBoxSizer *mainColumn)
 {
     m_sizerBmpAndPage = new wxBoxSizer(wxHORIZONTAL);