Fix reference counting in ProcessSystemExit. See https://en.delphipraxis.net/topic/11182-tpydelphiwrapper-memory-leaks/.

Author: pyscripter

Source/PythonEngine.pas

@@ -6425,15 +6425,19 @@ procedure TPythonEngine.ListToSet( List : PPyObject; data : Pointer; size : Inte
 end;
 
 procedure TPythonEngine.CheckError(ACatchStopEx : Boolean = False);
+
   procedure ProcessSystemExit;
   var
     errtype, errvalue, errtraceback: PPyObject;
     SErrValue: string;
   begin
+    // PyErr_Fetch clears the error. The returned python objects are new references
     PyErr_Fetch(errtype, errvalue, errtraceback);
     Traceback.Refresh(errtraceback);
     SErrValue := PyObjectAsString(errvalue);
-    PyErr_Clear;
+    Py_XDECREF(errtype);
+    Py_XDECREF(errvalue);
+    Py_XDECREF(errtraceback);
     raise EPySystemExit.CreateResFmt(@SPyExcSystemError, [SErrValue]);
   end;