Added macro CPY_SUBSTITUTE.

diff --git a/src/cpython.h b/src/cpython.h
index 001a3ae..10a1a54 100644 (file)
--- a/src/cpython.h
+++ b/src/cpython.h
@@ -74,6 +74,20 @@
 # define Py_RETURN_NONE return Py_INCREF(Py_None), Py_None
 #endif
 
+/* This macro is a shortcut for calls like
+ * x = PyObject_Repr(x);
+ * This can't be done like this example because this would leak
+ * a reference the the original x and crash in case of x == NULL.
+ * This calling syntax is less than elegant but it works, saves
+ * a lot of lines and avoids potential refcount errors. */
+
+#define CPY_SUBSTITUTE(func, a, ...) do {\
+       if ((a) != NULL) {\
+               PyObject *tmp = (a);\
+               (a) = func(__VA_ARGS__);\
+               Py_DECREF(tmp);\
+       }\
+} while(0)
 
 /* Python3 compatibility layer. To keep the actual code as clean as possible
  * do a lot of defines here. */

diff --git a/src/pyconfig.c b/src/pyconfig.c
index d794c9a..53e80e4 100644 (file)
--- a/src/pyconfig.c
+++ b/src/pyconfig.c
@@ -120,7 +120,7 @@ static int Config_init(PyObject *s, PyObject *args, PyObject *kwds) {
 
 static PyObject *Config_repr(PyObject *s) {
        Config *self = (Config *) s;
-       PyObject *name, *tmp, *ret = NULL;
+       PyObject *ret = NULL;
        static PyObject *node_prefix = NULL, *root_prefix = NULL, *ending = NULL;
        
        /* This is ok because we have the GIL, so this is thread-save by default. */
@@ -133,19 +133,12 @@ static PyObject *Config_repr(PyObject *s) {
        if (node_prefix == NULL || root_prefix == NULL || ending == NULL)
                return NULL;
        
-       name = PyObject_Str(self->key);
-       if (name == NULL)
-               return NULL;
-
+       ret = PyObject_Str(self->key);
        if (self->parent == NULL || self->parent == Py_None)
-               tmp = CPY_STRCAT(root_prefix, name);
+               CPY_SUBSTITUTE(CPY_STRCAT, ret, root_prefix, ret);
        else
-               tmp = CPY_STRCAT(node_prefix, name);
-       
-       Py_DECREF(name);
-       if (tmp != NULL)
-               ret = CPY_STRCAT(tmp, ending);
-       Py_DECREF(tmp);
+               CPY_SUBSTITUTE(CPY_STRCAT, ret, node_prefix, ret);
+       CPY_SUBSTITUTE(CPY_STRCAT, ret, ret, ending);
        
        return ret;
 }