diff --git a/ChangeLog b/ChangeLog
index 81117baac1..3decdaf461 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+Thu Aug 19 12:04:39 2010  Kenta Murata  <mrkn@mrkn.jp>
+
+	* array.c (rb_ary_permutation, rb_ary_repeated_permutation,
+	  rb_ary_repeated_combination, rb_ary_product):
+	  use ary_make_shared_copy instead of ary_make_substitution.
+	  [ruby-dev:42067] [Bug #3708]
+
+	* test/ruby/test_array.rb (test_product, test_repeated_permutation,
+	  test_repeated_combination): append assertions against [Bug #3708].
+
 Thu Aug 19 11:11:24 2010  NARUSE, Yui  <naruse@ruby-lang.org>
 
 	* enum.c (enum_inject): fix typo of rdoc.
diff --git a/array.c b/array.c
index 51d3ad262a..bca79566e1 100644
--- a/array.c
+++ b/array.c
@@ -4010,7 +4010,7 @@ rb_ary_permutation(int argc, VALUE *argv, VALUE ary)
 	long *p = (long*)RSTRING_PTR(t0);
 	volatile VALUE t1 = tmpbuf(n,sizeof(char));
 	char *used = (char*)RSTRING_PTR(t1);
-	VALUE ary0 = ary_make_substitution(ary); /* private defensive copy of ary */
+	VALUE ary0 = ary_make_shared_copy(ary); /* private defensive copy of ary */
 	RBASIC(ary0)->klass = 0;
 
 	MEMZERO(used, char, n); /* initialize array */
@@ -4180,7 +4180,7 @@ rb_ary_repeated_permutation(VALUE ary, VALUE num)
     else {             /* this is the general case */
 	volatile VALUE t0 = tmpbuf(r, sizeof(long));
 	long *p = (long*)RSTRING_PTR(t0);
-	VALUE ary0 = ary_make_substitution(ary); /* private defensive copy of ary */
+	VALUE ary0 = ary_make_shared_copy(ary); /* private defensive copy of ary */
 	RBASIC(ary0)->klass = 0;
 
 	rpermute0(n, r, p, 0, ary0); /* compute and yield repeated permutations */
@@ -4266,7 +4266,7 @@ rb_ary_repeated_combination(VALUE ary, VALUE num)
     else {
 	volatile VALUE t0 = tmpbuf(n, sizeof(long));
 	long *p = (long*)RSTRING_PTR(t0);
-	VALUE ary0 = ary_make_substitution(ary); /* private defensive copy of ary */
+	VALUE ary0 = ary_make_shared_copy(ary); /* private defensive copy of ary */
 	RBASIC(ary0)->klass = 0;
 
 	rcombinate0(len, n, p, 0, n, ary0); /* compute and yield repeated combinations */
@@ -4325,7 +4325,7 @@ rb_ary_product(int argc, VALUE *argv, VALUE ary)
 	/* Make defensive copies of arrays; exit if any is empty */
 	for (i = 0; i < n; i++) {
 	    if (RARRAY_LEN(arrays[i]) == 0) goto done;
-	    arrays[i] = ary_make_substitution(arrays[i]);
+	    arrays[i] = ary_make_shared_copy(arrays[i]);
 	}
     }
     else {
diff --git a/test/ruby/test_array.rb b/test/ruby/test_array.rb
index f2d723ffc9..3e32175012 100644
--- a/test/ruby/test_array.rb
+++ b/test/ruby/test_array.rb
@@ -1528,6 +1528,10 @@ class TestArray < Test::Unit::TestCase
     acc = [1,2].product(*[o]*10)
     assert_equal([1,2].product([3,4], [3,4], [3,4], [3,4], [3,4], [3,4], [3,4], [3,4], [3,4], [3,4]),
                  acc)
+
+    a = []
+    [1, 2].product([0, 1, 2, 3, 4][1, 4]) {|x| a << x }
+    assert(a.all?{|x| !x.include?(0) })
   end
 
   def test_permutation
@@ -1574,6 +1578,9 @@ class TestArray < Test::Unit::TestCase
     a.repeated_permutation(4) {|x| b << x; a.replace(@cls[9, 8, 7, 6]) }
     assert_equal(@cls[9, 8, 7, 6], a)
     assert_equal(@cls[1, 2, 3, 4].repeated_permutation(4).to_a, b)
+
+    a = @cls[0, 1, 2, 3, 4][1, 4].repeated_permutation(2)
+    assert(a.all?{|x| !x.include?(0) })
   end
 
   def test_repeated_combination
@@ -1600,6 +1607,9 @@ class TestArray < Test::Unit::TestCase
     a.repeated_combination(4) {|x| b << x; a.replace(@cls[9, 8, 7, 6]) }
     assert_equal(@cls[9, 8, 7, 6], a)
     assert_equal(@cls[1, 2, 3, 4].repeated_combination(4).to_a, b)
+
+    a = @cls[0, 1, 2, 3, 4][1, 4].repeated_combination(2)
+    assert(a.all?{|x| !x.include?(0) })
   end
 
   def test_take