Fix mouse dragging bug. Backport from develbranch_6 r39709.

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@39711 15284696-431f-4ddb-bdfa-cd5b030d7da7

gui/wxpython/gui_modules/mapdisp_window.py

@@ -345,8 +345,7 @@ class BufferedWindow(MapWindow, wx.Window):
             if self.pen:
                 pdc.SetBrush(wx.Brush(wx.CYAN, wx.TRANSPARENT))
                 pdc.SetPen(self.pen)
-                pdc.DrawLine(wx.Point(coords[0], coords[1]),
-                             wx.Point(coords[2], coords[3]))
+                pdc.DrawLinePoint(wx.Point(coords[0], coords[1]),wx.Point(coords[2], coords[3]))
                 pdc.SetIdBounds(drawid, wx.Rect(coords[0], coords[1], coords[2], coords[3]))
                 # self.ovlcoords[drawid] = coords