* array.c (flatten): check if reentered. [ruby-dev:34798]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@16522 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,7 @@
+Thu May 22 12:40:54 2008  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* array.c (flatten): check if reentered.  [ruby-dev:34798]
+
 Thu May 22 11:39:59 2008  Tanaka Akira  <akr@fsij.org>
 
 	* test/ruby/envutil.rb (assert_normal_exit): capture stdout and stderr

array.c

@@ -2831,8 +2831,8 @@ flatten(VALUE ary, int level, int *modified)
     st_table *memo;
     st_data_t id;
 
-    stack = rb_ary_new();
-    result = ary_new(rb_class_of(ary), RARRAY_LEN(ary));
+    stack = ary_new(0, ARY_DEFAULT_SIZE);
+    result = ary_new(0, RARRAY_LEN(ary));
     memo = st_init_numtable();
     st_insert(memo, (st_data_t)ary, (st_data_t)Qtrue);
     *modified = 0;
@@ -2841,6 +2841,9 @@ flatten(VALUE ary, int level, int *modified)
 	while (i < RARRAY_LEN(ary)) {
 	    elt = RARRAY_PTR(ary)[i++];
 	    tmp = rb_check_array_type(elt);
+	    if (RBASIC(result)->klass) {
+		rb_raise(rb_eRuntimeError, "flatten reentered");
+	    }
 	    if (NIL_P(tmp) || (level >= 0 && RARRAY_LEN(stack) / 2 >= level)) {
 		rb_ary_push(result, elt);
 	    }
@@ -2870,6 +2873,7 @@ flatten(VALUE ary, int level, int *modified)
 
     st_free_table(memo);
 
+    RBASIC(result)->klass = rb_class_of(ary);
     return result;
 }
 

test/ruby/test_array.rb

@@ -726,6 +726,20 @@ class TestArray < Test::Unit::TestCase
                  @cls[@cls[@cls[@cls[],@cls[]],@cls[@cls[]],@cls[]],@cls[@cls[@cls[]]]].flatten)
   end
 
+  def test_flatten_with_callcc
+    respond_to?(:callcc) or require 'continuation'
+    o = Object.new
+    def o.to_ary() callcc {|k| @cont = k; [1,2,3]} end
+    begin
+      assert_equal([10, 20, 1, 2, 3, 30, 1, 2, 3, 40], [10, 20, o, 30, o, 40].flatten)
+    rescue => e
+    else
+      o.instance_eval {@cont}.call
+    end
+    assert_instance_of(RuntimeError, e, '[ruby-dev:34798]')
+    assert_match(/reentered/, e.message, '[ruby-dev:34798]')
+  end
+
   def test_hash
     a1 = @cls[ 'cat', 'dog' ]
     a2 = @cls[ 'cat', 'dog' ]