Rewrote wxMSW radio menu items code to support not only appending them.

Previously the radio menu items could only be appended to a menu in wxMSW,
inserting them (either in an existing radio group or to start a new one) not
only didn't work but could even result in crashes because invalid iterators in
the menu items list could be used.

Fix this by storing the ranges of all radio groups in wxMenu itself instead of
storing the information about the radio group an item belongs to in the item
itself and by updating this data whenever a new radio item is inserted. Also
get rid of the notion of "current radio group" in wxMenu which doesn't really
make any sense.

Finally add a unit test checking that inserting radio items works as expected.

Closes #13200.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@67720 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/msw/menu.h

@@ -25,6 +25,7 @@ class WXDLLIMPEXP_FWD_CORE wxFrame;
 class WXDLLIMPEXP_FWD_CORE wxToolBar;
 #endif
 
+class wxMenuRadioItemsData;
 
 // Not using a combined wxToolBar/wxMenuBar? then use
 // a commandbar in WinCE .NET to implement the
@@ -63,13 +64,16 @@ public:
     // implementation only from now on
     // -------------------------------
 
-    virtual void Attach(wxMenuBarBase *menubar);
-
     bool MSWCommand(WXUINT param, WXWORD id);
 
     // get the native menu handle
     WXHMENU GetHMenu() const { return m_hMenu; }
 
+    // Return the start and end position of the radio group to which the item
+    // at the given position belongs. Returns false if there is no radio group
+    // containing this position.
+    bool MSWGetRadioGroupRange(int pos, int *start, int *end) const;
+
 #if wxUSE_ACCEL
     // called by wxMenuBar to build its accel table from the accels of all menus
     bool HasAccels() const { return !m_accels.empty(); }
@@ -122,15 +126,17 @@ private:
     // common part of Append/Insert (behaves as Append is pos == (size_t)-1)
     bool DoInsertOrAppend(wxMenuItem *item, size_t pos = (size_t)-1);
 
-    // terminate the current radio group, if any
-    void EndRadioGroup();
+
+    // This variable contains the description of the radio item groups and
+    // allows to find whether an item at the given position is part of the
+    // group and also where its group starts and ends.
+    //
+    // It is initially NULL and only allocated if we have any radio items.
+    wxMenuRadioItemsData *m_radioData;
 
     // if true, insert a breal before appending the next item
     bool m_doBreak;
 
-    // the position of the first item in the current radio group or -1
-    int m_startRadioGroup;
-
     // the menu handle of this menu
     WXHMENU m_hMenu;