In symtable_update_free_vars() do not modify the dictionary while

iterating over it using PyDict_Next().

This bug fix brought to you by the letters b, c, d, g, h, ... and the
reporter Ping.

diff --git a/Python/compile.c b/Python/compile.c
index 8370e0917517c73c0fdbfb2d5ac78b29aa6f3499..916c4a687d2ffcd455beacc3f138d79030d4f21e 100644 (file)
--- a/Python/compile.c
+++ b/Python/compile.c
@@ -4205,8 +4205,8 @@ PySymtable_Free(struct symtable *st)
 static int
 symtable_update_free_vars(struct symtable *st)
 {
-       PyObject *o, *name;
-       int i, def;
+       int i, j, def;
+       PyObject *o, *name, *list = NULL;
        PySymtableEntryObject *child, *ste = st->st_cur;
 
        if (ste->ste_type == TYPE_CLASS)
@@ -4216,25 +4216,45 @@ symtable_update_free_vars(struct symtable *st)
        for (i = 0; i < PyList_GET_SIZE(ste->ste_children); ++i) {
                int pos = 0;
 
+               if (list)
+                       PyList_SetSlice(list, 0, 
+                                       ((PyVarObject*)list)->ob_size, 0);
                child = (PySymtableEntryObject *)\
                        PyList_GET_ITEM(ste->ste_children, i);
                while (PyDict_Next(child->ste_symbols, &pos, &name, &o)) {
                        int v = PyInt_AS_LONG(o);
                        if (!(is_free(v)))
                                continue; /* avoids indentation */
+                       if (list == NULL) {
+                               list = PyList_New(0);
+                               if (list == NULL)
+                                       return -1;
+                       }
                        ste->ste_child_free = 1;
+                       if (PyList_Append(list, name) < 0) {
+                               Py_DECREF(list);
+                               return -1;
+                       }
+               }
+               for (j = 0; list && j < PyList_GET_SIZE(list); j++) {
+                       name = PyList_GET_ITEM(list, j);
                        if (ste->ste_nested) {
                                if (symtable_add_def_o(st, ste->ste_symbols,
-                                                      name, def) < 0)
-                                               return -1;
+                                                      name, def) < 0) {
+                                   Py_DECREF(list);
+                                   return -1;
+                               }
                        } else {
                                if (symtable_check_global(st, child->ste_id, 
-                                                         name) < 0)
-                                               return -1;
+                                                         name) < 0) {
+                                   Py_DECREF(list);
+                                   return -1;
+                               }
                        }
                }
        }
-               
+
+       Py_XDECREF(list);
        return 0;
 }