Proper Joins with c-treeSQL LONGVAR Fields

It was found that a c-treeSQL query joining two tables and selecting a LONGVAR field could return the wrong result. When performing a join, c-treeSQL may not fetch the LONGVAR field until the end of the join process when the field handle has already been closed. An error that should have been returned in this case was not properly passed to the client, thus resulting in an incorrect return value.

To correct the problem of the closed field handle, c-treeSQL now stores the table uid allowing a later fetch to properly re-open the table and use the appropriate field handle. Should this field handle unexpectedly become invalid, the error condition is also now properly passed to the client application.