diff --git a/ChangeLog b/ChangeLog
index 69c7cedb50..895609600c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Wed Jun  6 15:09:00 2012  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* eval.c (rb_thread_join), ext/thread/thread.c (wake_one): adjusts
+	  targets of rest waiting threads to join.  [ruby-core:23457]
+
 Wed Jun  6 14:44:13 2012  Kenta Murata  <mrkn@mrkn.jp>
 
 	* bignum.c (rb_big2dbl), test/ruby/test_bignum.rb (test_to_f):
diff --git a/eval.c b/eval.c
index 7886e17d1a..c350159e3e 100644
--- a/eval.c
+++ b/eval.c
@@ -11566,6 +11566,16 @@ rb_thread_join(thread, limit)
     return rb_thread_join0(rb_thread_check(thread), limit);
 }
 
+void
+rb_thread_set_join(thread, join)
+    VALUE thread, join;
+{
+    rb_thread_t th = rb_thread_check(thread);
+    rb_thread_t jth = rb_thread_check(join);
+    th->wait_for = WAIT_JOIN;
+    th->join = jth;
+}
+
 
 /*
  *  call-seq:
diff --git a/ext/thread/thread.c b/ext/thread/thread.c
index 298d7d08ca..b977fa77cf 100644
--- a/ext/thread/thread.c
+++ b/ext/thread/thread.c
@@ -205,6 +205,16 @@ array_from_list(List const *list)
     return ary;
 }
 
+static void
+adjust_join(const List *list, VALUE new)
+{
+    extern void rb_thread_set_join _((VALUE, VALUE));
+    Entry *entry;
+    for (entry = list->entries; entry; entry = entry->next) {
+	rb_thread_set_join(entry->value, new);
+    }
+}
+
 static VALUE
 wake_thread(VALUE thread)
 {
@@ -221,7 +231,7 @@ run_thread(VALUE thread)
 }
 
 static VALUE
-wake_one(List *list)
+wake_first(List *list)
 {
     VALUE waking;
 
@@ -233,11 +243,23 @@ wake_one(List *list)
     return waking;
 }
 
+static VALUE
+wake_one(List *list)
+{
+    VALUE waking = wake_first(list);
+
+    if (!NIL_P(waking)) {
+	adjust_join(list, waking);
+    }
+
+    return waking;
+}
+
 static VALUE
 wake_all(List *list)
 {
     while (list->entries) {
-        wake_one(list);
+        wake_first(list);
     }
     return Qnil;
 }
diff --git a/test/thread/test_thread.rb b/test/thread/test_thread.rb
index 699f4fe406..e3246d149c 100644
--- a/test/thread/test_thread.rb
+++ b/test/thread/test_thread.rb
@@ -86,5 +86,68 @@ class TC_Thread < Test::Unit::TestCase
         assert_nothing_raised("[ruby-dev:37545]") {assert_equal(1, queue.pop)}
         assert(queue.empty?)
     end
+
+  # This test checks that a thread in Mutex#lock which is raised is
+  # completely removed from the wait_list of the mutex
+  def test_mutex_exception_handling
+    m = Mutex.new
+    m.lock
+
+    sleeping = false
+    t = Thread.new do
+      begin
+        m.lock
+      rescue
+      end
+
+      sleeping = true
+      # Keep that thread alive: if the thread returns, the test method
+      # won't be able to check that +m+ has not been taken (dead mutex
+      # owners are ignored)
+      sleep
+    end
+
+    # Wait for t to wait for the mutex and raise it
+    while true
+      sleep 0.1
+      break if t.stop?
+    end
+    t.raise ArgumentError
+    assert(t.alive? || sleeping)
+
+    # Wait for +t+ to reach the sleep
+    while true
+      sleep 0.1
+      break if t.stop?
+    end
+
+    # Now unlock. The mutex should be free, so Mutex#unlock should return nil
+    assert(! m.unlock)
+  end
+
+  def test_mutex_join
+    m = Mutex.new
+    m.lock
+    wt2 = Thread.new do
+      m.lock
+      sleep 0.5
+      m.unlock
+    end
+
+    # Ensure wt2 is waiting on m
+    sleep 0.1
+
+    wt1 = Thread.new do
+      m.lock
+      m.unlock
+    end
+    # Ensure wt1 is waiting on m
+    sleep 0.1
+
+    # Give it to wt2
+    m.unlock
+
+    assert_nothing_raised {wt1.join}
+  end
 end
 
diff --git a/version.h b/version.h
index 3d64d07564..293cd6e7b6 100644
--- a/version.h
+++ b/version.h
@@ -2,7 +2,7 @@
 #define RUBY_RELEASE_DATE "2012-06-06"
 #define RUBY_VERSION_CODE 187
 #define RUBY_RELEASE_CODE 20120606
-#define RUBY_PATCHLEVEL 365
+#define RUBY_PATCHLEVEL 366
 
 #define RUBY_VERSION_MAJOR 1
 #define RUBY_VERSION_MINOR 8