* lib/set.rb (Set#replace): Check if an object given is enumerable

before clearing self.  Reported by yui-knk. [GH-675]
  https://github.com/ruby/ruby/pull/675

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47085 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,9 @@
+Wed Aug  6 20:25:47 2014  Akinori MUSHA  <knu@iDaemons.org>
+
+	* lib/set.rb (Set#replace): Check if an object given is enumerable
+	  before clearing self.  Reported by yui-knk. [GH-675]
+	  https://github.com/ruby/ruby/pull/675
+
 Wed Aug  6 20:07:26 2014  Masaki Suketa <masaki.suketa@nifty.ne.jp>
 
 	* ext/win32ole/win32ole.c (olerecord_ivar_set): remove rb_str_subseq.

lib/set.rb

@@ -91,9 +91,9 @@ class Set
 
   def do_with_enum(enum, &block) # :nodoc:
     if enum.respond_to?(:each_entry)
-      enum.each_entry(&block)
+      enum.each_entry(&block) if block
     elsif enum.respond_to?(:each)
-      enum.each(&block)
+      enum.each(&block) if block
     else
       raise ArgumentError, "value must be enumerable"
     end
@@ -149,12 +149,12 @@ class Set
   def replace(enum)
     if enum.instance_of?(self.class)
       @hash.replace(enum.instance_variable_get(:@hash))
+      self
     else
+      do_with_enum(enum)
       clear
       merge(enum)
     end
-
-    self
   end
 
   # Converts the set to an array.  The order of elements is uncertain.

test/test_set.rb

@@ -98,6 +98,12 @@ class TC_Set < Test::Unit::TestCase
 
     assert_same(set, ret)
     assert_equal(Set['a','b','c'], set)
+
+    set = Set[1,2]
+    assert_raise(ArgumentError) {
+      set.replace(3)
+    }
+    assert_equal(Set[1,2], set)
   end
 
   def test_to_a