diff --git a/ChangeLog b/ChangeLog
index 36cf859c34..ff25df39ff 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Sun Oct 21 18:29:17 2007  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* encoding.c (rb_enc_default, rb_enc_primary): return pointers to
+	  rb_encoding of default and primary respectively.  [ruby-core:12795]
+
+	* encoding.c (set_primary_encoding): removed primary_encoding setter.
+
 Sat Oct 20 11:49:20 2007  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* file.c (rb_get_path): returns frozen string.
diff --git a/encoding.c b/encoding.c
index a67e49fefb..3de7fcf3d3 100644
--- a/encoding.c
+++ b/encoding.c
@@ -48,6 +48,7 @@ VALUE
 rb_enc_from_encoding(rb_encoding *encoding)
 {
     VALUE enc;
+    if (!encoding) return 0;
     if (enc_initialized_p(encoding))
 	return ENC_FROM_ENCODING(encoding);
     enc = enc_new(encoding);
@@ -524,12 +525,27 @@ enc_load(VALUE klass, VALUE str)
     return enc_find(klass, str);
 }
 
-static VALUE rb_primary_encoding;
+static int primary_encoding_index;
+
+rb_encoding *
+rb_enc_default(void)
+{
+    if (!enc_table) {
+	rb_enc_init();
+    }
+    return enc_table[0].enc;
+}
+
+rb_encoding *
+rb_enc_primary(void)
+{
+    return rb_enc_from_index(primary_encoding_index);
+}
 
 VALUE
 rb_get_primary_encoding(void)
 {
-    return rb_primary_encoding;
+    return rb_enc_from_encoding(rb_enc_primary());
 }
 
 static VALUE
@@ -542,14 +558,7 @@ void
 rb_set_primary_encoding(VALUE encoding)
 {
     rb_to_encoding(encoding);
-    rb_primary_encoding = encoding;
-}
-
-static VALUE
-set_primary_encoding(VALUE klass, VALUE enc)
-{
-    rb_set_primary_encoding(enc);
-    return rb_primary_encoding;
+    primary_encoding_index = ENCODING_GET(encoding);
 }
 
 static void
@@ -616,9 +625,7 @@ Init_Encoding(void)
     rb_define_method(rb_cEncoding, "_dump", enc_dump, -1);
     rb_define_singleton_method(rb_cEncoding, "_load", enc_load, 1);
 
-    rb_primary_encoding = rb_enc_from_encoding(rb_enc_from_index(0));
     rb_define_singleton_method(rb_cEncoding, "primary_encoding", get_primary_encoding, 0);
-    rb_define_singleton_method(rb_cEncoding, "primary_encoding=", set_primary_encoding, 1);
 
     for (i = 0; i < enc_table_size; ++i) {
 	rb_encoding *enc = enc_table[i].enc;
diff --git a/include/ruby/encoding.h b/include/ruby/encoding.h
index 08371cc141..0d02c88459 100644
--- a/include/ruby/encoding.h
+++ b/include/ruby/encoding.h
@@ -100,6 +100,8 @@ ID rb_intern3(const char*, long, rb_encoding*);
 int rb_enc_symname_p(const char*, rb_encoding*);
 int rb_enc_str_coderange(VALUE);
 VALUE rb_enc_from_encoding(rb_encoding *enc);
+rb_encoding *rb_enc_primary(void);
+rb_encoding *rb_enc_default(void);
 VALUE rb_get_primary_encoding(void);
 void rb_set_primary_encoding(VALUE encoding);
 
diff --git a/version.h b/version.h
index 0e6e369f49..995c667ce3 100644
--- a/version.h
+++ b/version.h
@@ -1,7 +1,7 @@
 #define RUBY_VERSION "1.9.0"
-#define RUBY_RELEASE_DATE "2007-10-20"
+#define RUBY_RELEASE_DATE "2007-10-21"
 #define RUBY_VERSION_CODE 190
-#define RUBY_RELEASE_CODE 20071020
+#define RUBY_RELEASE_CODE 20071021
 #define RUBY_PATCHLEVEL 0
 
 #define RUBY_VERSION_MAJOR 1
@@ -9,7 +9,7 @@
 #define RUBY_VERSION_TEENY 0
 #define RUBY_RELEASE_YEAR 2007
 #define RUBY_RELEASE_MONTH 10
-#define RUBY_RELEASE_DAY 20
+#define RUBY_RELEASE_DAY 21
 
 #ifdef RUBY_EXTERN
 RUBY_EXTERN const char ruby_version[];