diff --git a/ChangeLog b/ChangeLog
index edbf2e1f12..b15c38d79d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Sun Sep 20 11:11:34 2009  Marc-Andre Lafortune  <ruby-core@marc-andre.ca>
+
+	* struct.c (rb_struct_equal, rb_struct_eql): Handle comparison of
+	  recursive structures [ruby-core:24759]
+
+	* range.c (range_eq, range_eql):  ditto for ranges
+
 Fri Sep 18 23:51:17 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* marshal.c (r_object0): entry regexp object before its encoding
diff --git a/range.c b/range.c
index 1e66bba856..1e68dbaff9 100644
--- a/range.c
+++ b/range.c
@@ -105,6 +105,20 @@ range_exclude_end_p(VALUE range)
     return EXCL(range) ? Qtrue : Qfalse;
 }
 
+static VALUE
+recursive_equal(VALUE range, VALUE obj, int recur)
+{
+    if (recur) return Qtrue; /* Subtle! */
+    if (!rb_equal(RANGE_BEG(range), RANGE_BEG(obj)))
+	return Qfalse;
+    if (!rb_equal(RANGE_END(range), RANGE_END(obj)))
+	return Qfalse;
+
+    if (EXCL(range) != EXCL(obj))
+	return Qfalse;
+    return Qtrue;
+}
+
 
 /*
  *  call-seq:
@@ -128,15 +142,7 @@ range_eq(VALUE range, VALUE obj)
     if (!rb_obj_is_kind_of(obj, rb_cRange))
 	return Qfalse;
 
-    if (!rb_equal(RANGE_BEG(range), RANGE_BEG(obj)))
-	return Qfalse;
-    if (!rb_equal(RANGE_END(range), RANGE_END(obj)))
-	return Qfalse;
-
-    if (EXCL(range) != EXCL(obj))
-	return Qfalse;
-
-    return Qtrue;
+    return rb_exec_recursive_paired(recursive_equal, range, obj, obj);
 }
 
 static int
@@ -168,6 +174,20 @@ r_le(VALUE a, VALUE b)
 }
 
 
+static VALUE
+recursive_eql(VALUE range, VALUE obj, int recur)
+{
+    if (recur) return Qtrue; /* Subtle! */
+    if (!rb_eql(RANGE_BEG(range), RANGE_BEG(obj)))
+	return Qfalse;
+    if (!rb_eql(RANGE_END(range), RANGE_END(obj)))
+	return Qfalse;
+
+    if (EXCL(range) != EXCL(obj))
+	return Qfalse;
+    return Qtrue;
+}
+
 /*
  *  call-seq:
  *     rng.eql?(obj)    => true or false
@@ -189,16 +209,7 @@ range_eql(VALUE range, VALUE obj)
 	return Qtrue;
     if (!rb_obj_is_kind_of(obj, rb_cRange))
 	return Qfalse;
-
-    if (!rb_eql(RANGE_BEG(range), RANGE_BEG(obj)))
-	return Qfalse;
-    if (!rb_eql(RANGE_END(range), RANGE_END(obj)))
-	return Qfalse;
-
-    if (EXCL(range) != EXCL(obj))
-	return Qfalse;
-
-    return Qtrue;
+    return rb_exec_recursive_paired(recursive_eql, range, obj, obj);
 }
 
 /*
diff --git a/struct.c b/struct.c
index 3d876bb216..79403a5fb6 100644
--- a/struct.c
+++ b/struct.c
@@ -760,6 +760,18 @@ rb_struct_select(int argc, VALUE *argv, VALUE s)
     return result;
 }
 
+static VALUE
+recursive_equal(VALUE s, VALUE s2, int recur)
+{
+    long i;
+
+    if (recur) return Qtrue; /* Subtle! */
+    for (i=0; i<RSTRUCT_LEN(s); i++) {
+	if (!rb_equal(RSTRUCT_PTR(s)[i], RSTRUCT_PTR(s2)[i])) return Qfalse;
+    }
+    return Qtrue;
+}
+
 /*
  *  call-seq:
  *     struct == other_struct     => true or false
@@ -780,8 +792,6 @@ rb_struct_select(int argc, VALUE *argv, VALUE s)
 static VALUE
 rb_struct_equal(VALUE s, VALUE s2)
 {
-    long i;
-
     if (s == s2) return Qtrue;
     if (TYPE(s2) != T_STRUCT) return Qfalse;
     if (rb_obj_class(s) != rb_obj_class(s2)) return Qfalse;
@@ -789,10 +799,7 @@ rb_struct_equal(VALUE s, VALUE s2)
 	rb_bug("inconsistent struct"); /* should never happen */
     }
 
-    for (i=0; i<RSTRUCT_LEN(s); i++) {
-	if (!rb_equal(RSTRUCT_PTR(s)[i], RSTRUCT_PTR(s2)[i])) return Qfalse;
-    }
-    return Qtrue;
+    return rb_exec_recursive_paired(recursive_equal, s, s2, s2);
 }
 
 /*
@@ -817,6 +824,18 @@ rb_struct_hash(VALUE s)
     return LONG2FIX(h);
 }
 
+static VALUE
+recursive_eql(VALUE s, VALUE s2, int recur)
+{
+    long i;
+
+    if (recur) return Qtrue; /* Subtle! */
+    for (i=0; i<RSTRUCT_LEN(s); i++) {
+	if (!rb_eql(RSTRUCT_PTR(s)[i], RSTRUCT_PTR(s2)[i])) return Qfalse;
+    }
+    return Qtrue;
+}
+
 /*
  * code-seq:
  *   struct.eql?(other)   => true or false
@@ -828,8 +847,6 @@ rb_struct_hash(VALUE s)
 static VALUE
 rb_struct_eql(VALUE s, VALUE s2)
 {
-    long i;
-
     if (s == s2) return Qtrue;
     if (TYPE(s2) != T_STRUCT) return Qfalse;
     if (rb_obj_class(s) != rb_obj_class(s2)) return Qfalse;
@@ -837,10 +854,7 @@ rb_struct_eql(VALUE s, VALUE s2)
 	rb_bug("inconsistent struct"); /* should never happen */
     }
 
-    for (i=0; i<RSTRUCT_LEN(s); i++) {
-	if (!rb_eql(RSTRUCT_PTR(s)[i], RSTRUCT_PTR(s2)[i])) return Qfalse;
-    }
-    return Qtrue;
+    return rb_exec_recursive_paired(recursive_eql, s, s2, s2);
 }
 
 /*
diff --git a/test/ruby/test_range.rb b/test/ruby/test_range.rb
index 9dfd29012a..dabe7fab87 100644
--- a/test/ruby/test_range.rb
+++ b/test/ruby/test_range.rb
@@ -1,4 +1,5 @@
 require 'test/unit'
+require 'timeout'
 
 class TestRange < Test::Unit::TestCase
   def test_range_string
@@ -280,4 +281,37 @@ class TestRange < Test::Unit::TestCase
     o.instance_eval { initialize(o, 1) }
     assert_equal("(... .. ...)..1", o.inspect)
   end
+
+  def test_comparison_when_recursive
+    x = CyclicRange.allocate; x.send(:initialize, x, 1)
+    y = CyclicRange.allocate; y.send(:initialize, y, 1)
+    Timeout.timeout(1) {
+      assert x == y
+      assert x.eql? y
+    }
+
+    z = CyclicRange.allocate; z.send(:initialize, z, :another)
+    Timeout.timeout(1) {
+      assert x != z
+      assert !x.eql?(z)
+    }
+
+    x = CyclicRange.allocate
+    y = CyclicRange.allocate
+    x.send(:initialize, y, 1)
+    y.send(:initialize, x, 1)
+    Timeout.timeout(1) {
+      assert x == y
+      assert x.eql?(y)
+    }
+
+    x = CyclicRange.allocate
+    z = CyclicRange.allocate
+    x.send(:initialize, z, 1)
+    z.send(:initialize, x, :other)
+    Timeout.timeout(1) {
+      assert x != z
+      assert !x.eql?(z)
+    }
+  end
 end
diff --git a/test/ruby/test_struct.rb b/test/ruby/test_struct.rb
index 1b68429d0c..688012a1fd 100644
--- a/test/ruby/test_struct.rb
+++ b/test/ruby/test_struct.rb
@@ -1,4 +1,5 @@
 require 'test/unit'
+require 'timeout'
 
 class TestStruct < Test::Unit::TestCase
   def test_struct
@@ -219,4 +220,33 @@ class TestStruct < Test::Unit::TestCase
     a = struct_test.new(42)
     assert_equal("#<struct Struct::R\u{e9}sum\u{e9} r\u{e9}sum\u{e9}=42>", a.inspect, '[ruby-core:24849]')
   end
+
+  def test_comparison_when_recursive
+    klass1 = Struct.new(:a, :b, :c)
+
+    x = klass1.new(1, 2, nil); x.c = x
+    y = klass1.new(1, 2, nil); y.c = y
+    Timeout.timeout(1) {
+      assert x == y
+      assert x.eql? y
+    }
+
+    z = klass1.new(:something, :other, nil); z.c = z
+    Timeout.timeout(1) {
+      assert x != z
+      assert !x.eql?(z)
+    }
+
+    x.c = y; y.c = x
+    Timeout.timeout(1) {
+      assert x == y
+      assert x.eql?(y)
+    }
+
+    x.c = z; z.c = x
+    Timeout.timeout(1) {
+      assert x != z
+      assert !x.eql?(z)
+    }
+  end
 end
diff --git a/version.h b/version.h
index bb6fca4c4e..f67ea54e42 100644
--- a/version.h
+++ b/version.h
@@ -1,5 +1,5 @@
 #define RUBY_VERSION "1.9.1"
-#define RUBY_PATCHLEVEL 344
+#define RUBY_PATCHLEVEL 345
 #define RUBY_VERSION_MAJOR 1
 #define RUBY_VERSION_MINOR 9
 #define RUBY_VERSION_TEENY 1