#19 Invalid column aliases get added on parse

[Thomas Morgner]

Editing a previously defined (and working) query with Query Designer messes with columns aliases. So, for instance, when editing a query such as:

select field1, field2 as alias2, field3, field4, field5 as alias5 from table

it becomes:

select field1, field2 as alias2, field3 as alias2, field4 as alias2, field5 as alias5 from table

The alias for field2 is replicated for the following columns without an alias.

@see http://jira.pentaho.com/browse/PRD-2351