slot_nb_nonzero(): Another leak uncovered by the sandbox datetime

tests.  I found the logic too confusing to follow here, so rewrote more
than was likely absolutely necessary.

Bugfix candidate.

diff --git a/Objects/typeobject.c b/Objects/typeobject.c
index 612944214ef74b205e9e24483ae963e9dbd1e76c..0b7f00d25907e31903107de6a585144afa4ba03c 100644 (file)
--- a/Objects/typeobject.c
+++ b/Objects/typeobject.c
@@ -43,7 +43,7 @@ type_name(PyTypeObject *type, void *context)
 
        if (type->tp_flags & Py_TPFLAGS_HEAPTYPE) {
                etype* et = (etype*)type;
-               
+
                Py_INCREF(et->name);
                return et->name;
        }
@@ -78,7 +78,7 @@ type_set_name(PyTypeObject *type, PyObject *value, void *context)
                             type->tp_name, value->ob_type->tp_name);
                return -1;
        }
-       if (strlen(PyString_AS_STRING(value)) 
+       if (strlen(PyString_AS_STRING(value))
            != (size_t)PyString_GET_SIZE(value)) {
                PyErr_Format(PyExc_ValueError,
                             "__name__ must not contain null bytes");
@@ -310,10 +310,10 @@ type_set_bases(PyTypeObject *type, PyObject *value, void *context)
        type->tp_bases = old_bases;
        type->tp_base = old_base;
        type->tp_mro = old_mro;
-       
+
        Py_DECREF(value);
        Py_DECREF(new_base);
-       
+
        return -1;
 }
 
@@ -884,21 +884,21 @@ classic_mro(PyObject *cls)
        return NULL;
 }
 
-/*  
+/*
     Method resolution order algorithm C3 described in
     "A Monotonic Superclass Linearization for Dylan",
     by Kim Barrett, Bob Cassel, Paul Haahr,
-    David A. Moon, Keith Playford, and P. Tucker Withington. 
+    David A. Moon, Keith Playford, and P. Tucker Withington.
     (OOPSLA 1996)
 
     Some notes about the rules implied by C3:
 
-    No duplicate bases. 
+    No duplicate bases.
     It isn't legal to repeat a class in a list of base classes.
 
     The next three properties are the 3 constraints in "C3".
 
-    Local precendece order.  
+    Local precendece order.
     If A precedes B in C's MRO, then A will precede B in the MRO of all
     subclasses of C.
 
@@ -912,7 +912,7 @@ classic_mro(PyObject *cls)
     the paper for definition of EPG.
  */
 
-static int 
+static int
 tail_contains(PyObject *list, int whence, PyObject *o) {
        int j, size;
        size = PyList_GET_SIZE(list);
@@ -1010,12 +1010,12 @@ set_mro_error(PyObject *to_merge, int *remain)
        Py_DECREF(set);
 }
 
-static int 
+static int
 pmerge(PyObject *acc, PyObject* to_merge) {
        int i, j, to_merge_size;
        int *remain;
        int ok, empty_cnt;
-       
+
        to_merge_size = PyList_GET_SIZE(to_merge);
 
        /* remain stores an index into each sublist of to_merge.
@@ -1032,7 +1032,7 @@ pmerge(PyObject *acc, PyObject* to_merge) {
        empty_cnt = 0;
        for (i = 0; i < to_merge_size; i++) {
                PyObject *candidate;
-               
+
                PyObject *cur_list = PyList_GET_ITEM(to_merge, i);
 
                if (remain[i] >= PyList_GET_SIZE(cur_list)) {
@@ -1092,7 +1092,7 @@ mro_implementation(PyTypeObject *type)
 
        /* Find a superclass linearization that honors the constraints
           of the explicit lists of bases and the constraints implied by
-          each base class.  
+          each base class.
 
           to_merge is a list of lists, where each list is a superclass
           linearization implied by a base class.  The last element of
@@ -2288,7 +2288,7 @@ compatible_for_assignment(PyTypeObject* old, PyTypeObject* new, char* attr)
                             old->tp_name);
                return 0;
        }
-       
+
        return 1;
 }
 
@@ -2355,7 +2355,7 @@ object_reduce(PyObject *self, PyObject *args)
 }
 
 static PyMethodDef object_methods[] = {
-       {"__reduce__", object_reduce, METH_NOARGS, 
+       {"__reduce__", object_reduce, METH_NOARGS,
         PyDoc_STR("helper for pickle")},
        {0}
 };
@@ -3734,30 +3734,29 @@ SLOT0(slot_nb_absolute, "__abs__")
 static int
 slot_nb_nonzero(PyObject *self)
 {
-       PyObject *func, *res, *args;
+       PyObject *func, *args;
        static PyObject *nonzero_str, *len_str;
+       int result = -1;
 
        func = lookup_maybe(self, "__nonzero__", &nonzero_str);
        if (func == NULL) {
                if (PyErr_Occurred())
                        return -1;
                func = lookup_maybe(self, "__len__", &len_str);
-               if (func == NULL) {
-                       if (PyErr_Occurred())
-                               return -1;
-                       else
-                               return 1;
-               }
-       }
-       args = res = PyTuple_New(0);
+               if (func == NULL)
+                       return PyErr_Occurred() ? -1 : 1;
+       }
+       args = PyTuple_New(0);
        if (args != NULL) {
-               res = PyObject_Call(func, args, NULL);
+               PyObject *temp = PyObject_Call(func, args, NULL);
                Py_DECREF(args);
+               if (temp != NULL) {
+                       result = PyObject_IsTrue(temp);
+                       Py_DECREF(temp);
+               }
        }
        Py_DECREF(func);
-       if (res == NULL)
-               return -1;
-       return PyObject_IsTrue(res);
+       return result;
 }
 
 SLOT0(slot_nb_invert, "__invert__")