[BUGFIX] - Issue 2797248/2799322 - Altered points used for checking tab dragging.

- The windows function checking for dragging was expecting screen coordinates and was getting
    client coordinates.  This caused incorrect checks for when a new instance needed to be created.

git-svn-id: svn://svn.tuxfamily.org/svnroot/notepadplus/repository/trunk@489 f5eea248-9336-0410-98b8-ebc06183d4e3

PowerEditor/src/WinControls/TabBar/TabBar.cpp

@@ -309,10 +309,11 @@ LRESULT TabBarPlus::runProc(HWND hwnd, UINT Message, WPARAM wParam, LPARAM lPara
             if (_doDragNDrop)
             {
                 _nSrcTab = _nTabDragged = currentTabOn;
-        
+
                 POINT point;
 			    point.x = LOWORD(lParam);
 			    point.y = HIWORD(lParam);
+				::ClientToScreen(hwnd, &point);
 			    if(::DragDetect(hwnd, point)) 
 			    {
 				    // Yes, we're beginning to drag, so capture the mouse...