Don't send explicit update event if single line

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@18400 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/msw/textctrl.cpp

@@ -756,6 +756,9 @@ void wxTextCtrl::DoWriteText(const wxString& value, bool selectionOnly)
 #endif // wxUSE_RICHEDIT
            )
         {
+            // Windows already sends an update event for single-line
+            // controls.
+            if ( m_windowStyle & wxTE_MULTILINE )
                 SendUpdateEvent();
         }
     }
@@ -790,6 +793,10 @@ void wxTextCtrl::Clear()
         // rich edit controls send EN_UPDATE from WM_SETTEXT handler themselves
         // but the normal ones don't -- make Clear() behaviour consistent by
         // always sending this event
+
+        // Windows already sends an update event for single-line
+        // controls.
+        if ( m_windowStyle & wxTE_MULTILINE )
             SendUpdateEvent();
     }
 }