Hack for wxWidgets failure to open menu on MSW.

common/tool/conditional_menu.cpp

@@ -27,6 +27,18 @@
 #include <tool/action_menu.h>
 
 
+CONDITIONAL_MENU::CONDITIONAL_MENU( bool isContextMenu, TOOL_INTERACTIVE* aTool ) :
+        m_isContextMenu( isContextMenu )
+{
+    m_tool = aTool;
+
+    // wxWidgets 3.0.4 on MSW checks for an empty menu before running the MENU_OPEN
+    // event.  Add a dummy item to ensure that the event is dispatched.  Evaluate()
+    // will clear the menu before evaluating all the items anyway.
+    Append( wxID_ANY, wxT( "dummy menu for MSW" ) );
+}
+
+
 ACTION_MENU* CONDITIONAL_MENU::create() const
 {
     CONDITIONAL_MENU* clone = new CONDITIONAL_MENU( m_isContextMenu, m_tool );

include/tool/conditional_menu.h

@@ -42,12 +42,7 @@ public:
     ///> Constant to indicate that we do not care about an ENTRY location in the menu.
     static const int ANY_ORDER = -1;
 
-
-    CONDITIONAL_MENU( bool isContextMenu, TOOL_INTERACTIVE* aTool ) :
-        m_isContextMenu( isContextMenu )
-    {
-        m_tool = aTool;
-    }
+    CONDITIONAL_MENU( bool isContextMenu, TOOL_INTERACTIVE* aTool );
 
     ACTION_MENU* create() const override;