* create a line, set quantity X
 * add a cell in the line, set quantity X on the cell (using edit)
 * edit will compare cell.getProperty("quantity") with the provided quantity
 * cell.getProperty is MappedValue.getProperty which uses getattr to get the
  "quantity" attribute on cell, which acquires it from line. As edit does not
  set the property if it's not different from what getProperty returns, the
  property is not edited.



git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@20843 20353a03-c40f-0410-a6d1-a30d3c3de9de