timeout.rb: fix for ExitException

* lib/timeout.rb (Timeout#timeout): should not rescue ordinarily
  raised ExitException, which should not be thrown.
* lib/timeout.rb (Timeout::ExitException.catch): set @thread only if
  it ought to be caught.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@44518 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

Conflicts:
	ChangeLog

Author: nobu

lib/timeout.rb

@@ -28,10 +28,11 @@ class Error < RuntimeError
   class ExitException < ::Exception # :nodoc:
     attr_reader :klass, :thread
 
-    def initialize(*)
-      super
-      @thread = Thread.current
-      freeze
+    def self.catch
+      exc = new
+      exc.instance_variable_set(:@thread, Thread.current)
+      exc.freeze
+      ::Kernel.catch(exc) {yield exc}
     end
 
     def exception(*)
@@ -80,16 +81,22 @@ def timeout(sec, klass = nil)   #:yield: +sec+
           end
         }
         return yield(sec)
-      rescue klass => e
-        e.backtrace
       ensure
         if y
           y.kill
           y.join # make sure y is dead.
         end
       end
     end
-    bt = klass ? bl.call(klass) : catch((klass = ExitException).new, &bl)
+    if klass
+      begin
+        bl.call(klass)
+      rescue klass => e
+        bt = e.backtrace
+      end
+    else
+      bt = ExitException.catch(&bl)
+    end
     rej = /\A#{Regexp.quote(__FILE__)}:#{__LINE__-4}\z/o
     bt.reject! {|m| rej =~ m}
     level = -caller(CALLER_OFFSET).size

test/test_timeout.rb

@@ -67,4 +67,12 @@ def initialize(msg) super end
       assert_equal(:ok, timeout(100, err) {:ok})
     end
   end
+
+  def test_exit_exception
+    assert_raise_with_message(Timeout::ExitException, "boon") do
+      Timeout.timeout(10, Timeout::ExitException) do
+        raise Timeout::ExitException, "boon"
+      end
+    end
+  end
 end