Make wxChoice and wxComboBox behaviour same as in native controls in wxMSW.

Keep the item selected from the drop down using keyboard when switching away
from the control by pressing TAB: although this generates CBN_SELENDCANCEL
notification, the selection is actually kept by the native controls in this
case, so don't reset it ourselves -- even though it makes sense, it makes wx
applications behave differently from the native ones.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@73103 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/msw/choice.h

@@ -106,7 +106,8 @@ protected:
     // common part of all ctors
     void Init()
     {
-        m_lastAcceptedSelection = wxID_NONE;
+        m_lastAcceptedSelection =
+        m_pendingSelection = wxID_NONE;
         m_heightOwn = wxDefaultCoord;
     }
 
@@ -162,10 +163,13 @@ protected:
     virtual void MSWEndDeferWindowPos();
 #endif // wxUSE_DEFERRED_SIZING
 
-    // last "completed" selection, i.e. not the transient one while the user is
-    // browsing the popup list: this is only used when != wxID_NONE which is
-    // the case while the drop down is opened
-    int m_lastAcceptedSelection;
+    // These variables are only used while the drop down is opened.
+    //
+    // The first one contains the item that had been originally selected before
+    // the drop down was opened and the second one the item we should select
+    // when the drop down is closed again.
+    int m_lastAcceptedSelection,
+        m_pendingSelection;
 
     // the height of the control itself if it was set explicitly or
     // wxDefaultCoord if it hadn't