Fix volatile vs. pointer confusion

Variables used after a longjmp() need to be declared volatile.  In
case of a pointer, it's the pointer itself that needs to be declared
volatile, not the pointed-to value.  So we need

    PyObject *volatile items;

instead of

    volatile PyObject *items;  /* wrong */

Discussion: https://www.postgresql.org/message-id/flat/f747368d-9e1a-c46a-ac76-3c27da32e8e4%402ndquadrant.com

1 files changed, 3 insertions, 6 deletions

diff --git a/contrib/jsonb_plpython/jsonb_plpython.c b/contrib/jsonb_plpython/jsonb_plpython.c
index f44d364c97c..1bc984d5c4d 100644
--- a/contrib/jsonb_plpython/jsonb_plpython.c
+++ b/contrib/jsonb_plpython/jsonb_plpython.c
@@ -237,17 +237,14 @@ PLyMapping_ToJsonbValue(PyObject *obj, JsonbParseState **jsonb_state)
 	JsonbValue *out = NULL;
 
 	/* We need it volatile, since we use it after longjmp */
-	volatile PyObject *items_v = NULL;
+	PyObject *volatile items = NULL;
 
 	pcount = PyMapping_Size(obj);
-	items_v = PyMapping_Items(obj);
+	items = PyMapping_Items(obj);
 
 	PG_TRY();
 	{
 		Py_ssize_t	i;
-		PyObject   *items;
-
-		items = (PyObject *) items_v;
 
 		pushJsonbValue(jsonb_state, WJB_BEGIN_OBJECT, NULL);
 
@@ -279,7 +276,7 @@ PLyMapping_ToJsonbValue(PyObject *obj, JsonbParseState **jsonb_state)
 	}
 	PG_CATCH();
 	{
-		Py_DECREF(items_v);
+		Py_DECREF(items);
 		PG_RE_THROW();
 	}
 	PG_END_TRY();