Fix three Python reference leaks in PLy_traceback(). This would result

in leaking memory when invoking a PL/Python procedure that raises an
exception. Unfortunately this still leaks memory, but at least the
largest leak has been plugged.

This patch also fixes a reference counting mistake in PLy_modify_tuple()
for 8.0, 8.1 and HEAD: we don't actually own a reference to `platt', so
we shouldn't Py_DECREF() it.

Author: Neil Conway

src/pl/plpython/plpython.c

@@ -29,7 +29,7 @@
  * MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
  *
  * IDENTIFICATION
- *	$PostgreSQL: pgsql/src/pl/plpython/plpython.c,v 1.70 2006/01/10 00:33:12 neilc Exp $
+ *	$PostgreSQL: pgsql/src/pl/plpython/plpython.c,v 1.71 2006/02/20 20:10:37 neilc Exp $
  *
  *********************************************************************
  */
@@ -543,7 +543,6 @@ PLy_modify_tuple(PLyProcedure * proc, PyObject * pltd, TriggerData *tdata,
 	{
 		Py_XDECREF(plntup);
 		Py_XDECREF(plkeys);
-		Py_XDECREF(platt);
 		Py_XDECREF(plval);
 		Py_XDECREF(plstr);
 
@@ -1068,7 +1067,7 @@ PLy_procedure_create(FunctionCallInfo fcinfo, Oid tgreloid,
 		}
 
 		/*
-		 * now get information required for input conversion of the procedures
+		 * now get information required for input conversion of the procedure's
 		 * arguments.
 		 */
 		proc->nargs = fcinfo->nargs;
@@ -2516,6 +2515,7 @@ PLy_traceback(int *xlevel)
 	}
 
 	PyErr_NormalizeException(&e, &v, &tb);
+	Py_XDECREF(tb);
 
 	eob = PyObject_Str(e);
 	if (v && ((vob = PyObject_Str(v)) != NULL))
@@ -2534,9 +2534,10 @@ PLy_traceback(int *xlevel)
 
 	Py_DECREF(eob);
 	Py_XDECREF(vob);
+	Py_XDECREF(v);
 
 	/*
-	 * intuit an appropriate error level for based on the exception type
+	 * intuit an appropriate error level based on the exception type
 	 */
 	if (PLy_exc_error && PyErr_GivenExceptionMatches(e, PLy_exc_error))
 		*xlevel = ERROR;
@@ -2545,6 +2546,7 @@ PLy_traceback(int *xlevel)
 	else
 		*xlevel = ERROR;
 
+	Py_DECREF(e);
 	return xstr;
 }