From 55e991b27ca40f5e1cdf33a85a27db5eff5f19d5 Mon Sep 17 00:00:00 2001
From: Nick Mathewson <nickm@torproject.org>
Date: Mon, 26 Mar 2012 17:35:21 -0400
Subject: [PATCH] Make libevent_global_shutdown() idempotent

Two calls to libevent_global_shutdown on your exit path shouldn't
result in a crash.
---
 event.c       | 1 +
 evutil_rand.c | 1 +
 signal.c      | 1 +
 3 files changed, 3 insertions(+)

diff --git a/event.c b/event.c
index bb4c4c88..0b78b743 100644
--- a/event.c
+++ b/event.c
@@ -3168,6 +3168,7 @@ event_free_debug_globals_locks(void)
 #ifndef EVENT__DISABLE_DEBUG_MODE
 	if (event_debug_map_lock_ != NULL) {
 		EVTHREAD_FREE_LOCK(event_debug_map_lock_, 0);
+		event_debug_map_lock_ = NULL;
 	}
 #endif /* EVENT__DISABLE_DEBUG_MODE */
 #endif /* EVENT__DISABLE_THREAD_SUPPORT */
diff --git a/evutil_rand.c b/evutil_rand.c
index 9259335c..dd566bac 100644
--- a/evutil_rand.c
+++ b/evutil_rand.c
@@ -124,6 +124,7 @@ evutil_free_secure_rng_globals_locks(void)
 #ifndef EVENT__DISABLE_THREAD_SUPPORT
 	if (arc4rand_lock != NULL) {
 		EVTHREAD_FREE_LOCK(arc4rand_lock, 0);
+		arc4rand_lock = NULL;
 	}
 #endif
 	return;
diff --git a/signal.c b/signal.c
index c8ae5c22..e5dd555e 100644
--- a/signal.c
+++ b/signal.c
@@ -455,6 +455,7 @@ evsig_free_globals_locks(void)
 #ifndef EVENT__DISABLE_THREAD_SUPPORT
 	if (evsig_base_lock != NULL) {
 		EVTHREAD_FREE_LOCK(evsig_base_lock, 0);
+		evsig_base_lock = NULL;
 	}
 #endif
 	return;