{
int res, old_count;
+ /*
+ * A NULL expr is taken to be yes, but there's also a different way to
+ * represent yes. expr_is_yes() checks for either representation.
+ */
+ if (!e1 || !e2)
+ return expr_is_yes(e1) && expr_is_yes(e2);
+
if (e1->type != e2->type)
return 0;
switch (e1->type) {