pgtcl - libpgtcl: * Fixed bug in "pgresult -assign" that could cuase a

[karl(at)pgfoundry(dot)org (User Karl)]

Log Message:
-----------
* Fixed bug in "pgresult -assign" that could cuase a Tcl panic by
  attempting to set a value into a shared Tcl object.

* libpq's PQfname can return NULL if the column requested is out of 
  range.  We have seen it return NULL when the column is in range,
  so instead of dumping core, we treat such a return as a Tcl error.

Modified Files:
--------------
    libpgtcl:
        ChangeLog (r1.57 -> r1.58)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgtcl/libpgtcl/ChangeLog?r1=1.57&r2=1.58)
    libpgtcl/generic:
        pgtclCmds.c (r1.73 -> r1.74)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgtcl/libpgtcl/generic/pgtclCmds.c?r1=1.73&r2=1.74)