Trace 0:
  Transitions:
    'when treating unknown struct PyObject * * from tests/cpychecker/refcounts/PyString_ConcatAndDel/null-rhs/input.c:27 as non-NULL'
    'when treating unknown struct PyObject * from tests/cpychecker/refcounts/PyString_ConcatAndDel/null-rhs/input.c:29 as non-NULL'
    'when PyString_Concat() cleans up due to NULL right-hand side (Py_DECREF() without deallocation on *LHS)'
    'returning'
  Return value:
    repr(): ConcreteValue(gcctype='struct PyObject *', loc=gcc.Location(file='tests/cpychecker/refcounts/PyString_ConcatAndDel/null-rhs/input.c', line=29), value=0)
    str(): (struct PyObject *)0 from tests/cpychecker/refcounts/PyString_ConcatAndDel/null-rhs/input.c:29
  Exception:
    (struct PyObject *)0 from tests/cpychecker/refcounts/PyString_ConcatAndDel/null-rhs/input.c:28

Trace 1:
  Transitions:
    'when treating unknown struct PyObject * * from tests/cpychecker/refcounts/PyString_ConcatAndDel/null-rhs/input.c:27 as non-NULL'
    'when treating unknown struct PyObject * from tests/cpychecker/refcounts/PyString_ConcatAndDel/null-rhs/input.c:29 as non-NULL'
    'when PyString_Concat() cleans up due to NULL right-hand side (Py_DECREF() with deallocation on *LHS)'
    'returning'
  Return value:
    repr(): ConcreteValue(gcctype='struct PyObject *', loc=gcc.Location(file='tests/cpychecker/refcounts/PyString_ConcatAndDel/null-rhs/input.c', line=29), value=0)
    str(): (struct PyObject *)0 from tests/cpychecker/refcounts/PyString_ConcatAndDel/null-rhs/input.c:29
  Exception:
    (struct PyObject *)0 from tests/cpychecker/refcounts/PyString_ConcatAndDel/null-rhs/input.c:28

Trace 2:
  Transitions:
    'when treating unknown struct PyObject * * from tests/cpychecker/refcounts/PyString_ConcatAndDel/null-rhs/input.c:27 as non-NULL'
    'when treating unknown struct PyObject * from tests/cpychecker/refcounts/PyString_ConcatAndDel/null-rhs/input.c:29 as NULL'
    'when PyString_Concat() does nothing due to NULL *lhs'
    'returning'
  Return value:
    repr(): ConcreteValue(gcctype='struct PyObject *', loc=gcc.Location(file='tests/cpychecker/refcounts/PyString_ConcatAndDel/null-rhs/input.c', line=29), value=0)
    str(): (struct PyObject *)0 from tests/cpychecker/refcounts/PyString_ConcatAndDel/null-rhs/input.c:29
  Exception:
    (struct PyObject *)0 from tests/cpychecker/refcounts/PyString_ConcatAndDel/null-rhs/input.c:28

Trace 3:
  Transitions:
    'when treating unknown struct PyObject * * from tests/cpychecker/refcounts/PyString_ConcatAndDel/null-rhs/input.c:27 as NULL'
  error: NullPtrArgument()
  error: possibly calling PyString_ConcatAndDel with NULL as argument 1 (str) at tests/cpychecker/refcounts/PyString_ConcatAndDel/null-rhs/input.c:29
  Exception:
    (struct PyObject *)0 from tests/cpychecker/refcounts/PyString_ConcatAndDel/null-rhs/input.c:28