merges r29155 from trunk into ruby_1_9_2. fixes #3777, #3772 and #3722.

--
* thread.c (ruby_suppress_tracing): restore the state and invoke
  the func with normal state.  a patch from Satoshi Shiba <shiba
  AT rvm.jp> at [ruby-dev:42162].  [ruby-core:31783]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_2@29574 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

test/ruby/test_trace.rb

@@ -46,4 +46,16 @@ class TestTrace < Test::Unit::TestCase
   ensure
     untrace_var :$x
   end
+
+  def test_trace_break
+    bug2722 = '[ruby-core:31783]'
+    a = Object.new.extend(Enumerable)
+    def a.each
+      yield
+    end
+    assert(Thread.start {
+             Thread.current.add_trace_func(proc{})
+             a.any? {true}
+           }.value, bug2722)
+  end
 end