+ /*
+ * The kill() above made the signal pending for us, as well as
+ * the rest of our process group, but we don't want it delivered
+ * to us. It is blocked at the moment. Setting it to be ignored
+ * will cause the pending signal to be discarded. If we did the
+ * kill() after setting the signal to be ignored, it is unspecified
+ * (by POSIX) whether the signal is immediately discarded or left
+ * pending, and in fact Linux would leave it pending, and so it
+ * would be delivered after the current signal handler exits,
+ * leading to an infinite loop.
+ */
+ sigaction(sig, &act, &oldact);