Plug leak of stack frame object in exception handling code.

Also delay DECREF calls until after the structures have been updated
(for reentrancy awareness).

diff --git a/Python/ceval.c b/Python/ceval.c
index ead65b91fb5bd37519c097923114ee1f95bd9e93..e8ba965c31766a688027821b9eda052c93b89d1c 100644 (file)
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -1755,31 +1755,41 @@ set_exc_info(tstate, type, value, tb)
        PyObject *tb;
 {
        PyFrameObject *frame;
+       PyObject *tmp_type, *tmp_value, *tmp_tb;
        frame = tstate->frame;
        if (frame->f_exc_type == NULL) {
                /* This frame didn't catch an exception before */
                /* Save previous exception of this thread in this frame */
-               Py_XDECREF(frame->f_exc_type);
-               Py_XDECREF(frame->f_exc_value);
-               Py_XDECREF(frame->f_exc_traceback);
                if (tstate->exc_type == NULL) {
                        Py_INCREF(Py_None);
                        tstate->exc_type = Py_None;
                }
+               tmp_type = frame->f_exc_type;
+               tmp_value = frame->f_exc_value;
+               tmp_tb = frame->f_exc_traceback;
                Py_XINCREF(tstate->exc_type);
                Py_XINCREF(tstate->exc_value);
                Py_XINCREF(tstate->exc_traceback);
                frame->f_exc_type = tstate->exc_type;
                frame->f_exc_value = tstate->exc_value;
                frame->f_exc_traceback = tstate->exc_traceback;
+               Py_XDECREF(tmp_type);
+               Py_XDECREF(tmp_value);
+               Py_XDECREF(tmp_tb);
        }
        /* Set new exception for this thread */
+       tmp_type = tstate->exc_type;
+       tmp_value = tstate->exc_value;
+       tmp_tb = tstate->exc_traceback;
        Py_XINCREF(type);
        Py_XINCREF(value);
        Py_XINCREF(tb);
        tstate->exc_type = type;
        tstate->exc_value = value;
        tstate->exc_traceback = tb;
+       Py_XDECREF(tmp_type);
+       Py_XDECREF(tmp_value);
+       Py_XDECREF(tmp_tb);
        /* For b/w compatibility */
        PySys_SetObject("exc_type", type);
        PySys_SetObject("exc_value", value);
@@ -1791,29 +1801,36 @@ reset_exc_info(tstate)
        PyThreadState *tstate;
 {
        PyFrameObject *frame;
+       PyObject *tmp_type, *tmp_value, *tmp_tb;
        frame = tstate->frame;
        if (frame->f_exc_type != NULL) {
                /* This frame caught an exception */
-               Py_XDECREF(tstate->exc_type);
-               Py_XDECREF(tstate->exc_value);
-               Py_XDECREF(tstate->exc_traceback);
+               tmp_type = tstate->exc_type;
+               tmp_value = tstate->exc_value;
+               tmp_tb = tstate->exc_traceback;
                Py_XINCREF(frame->f_exc_type);
                Py_XINCREF(frame->f_exc_value);
                Py_XINCREF(frame->f_exc_traceback);
                tstate->exc_type = frame->f_exc_type;
                tstate->exc_value = frame->f_exc_value;
                tstate->exc_traceback = frame->f_exc_traceback;
+               Py_XDECREF(tmp_type);
+               Py_XDECREF(tmp_value);
+               Py_XDECREF(tmp_tb);
                /* For b/w compatibility */
                PySys_SetObject("exc_type", frame->f_exc_type);
                PySys_SetObject("exc_value", frame->f_exc_value);
                PySys_SetObject("exc_traceback", frame->f_exc_traceback);
        }
-       Py_XDECREF(frame->f_exc_type);
-       Py_XDECREF(frame->f_exc_value);
-       Py_XDECREF(frame->f_exc_traceback);
+       tmp_type = frame->f_exc_type;
+       tmp_value = frame->f_exc_value;
+       tmp_tb = frame->f_exc_traceback;
        frame->f_exc_type = NULL;
        frame->f_exc_value = NULL;
        frame->f_exc_traceback = NULL;
+       Py_XDECREF(tmp_type);
+       Py_XDECREF(tmp_value);
+       Py_XDECREF(tmp_tb);
 }
 
 /* Logic for the raise statement (too complicated for inlining).