diff --git a/ChangeLog b/ChangeLog
index d74fbba50d..a42d42f9f6 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,17 @@
+Sat Jan  5 01:30:30 2008  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* include/ruby/intern.h, re.c (rb_reg_new): keep interface same as
+	  1.8.  [ruby-core:14583]
+
+	* include/ruby/intern.h, re.c (rb_reg_new_str): renamed, and defines
+	  HAVE_RB_REG_NEW_STR macro to tell if it is available.
+
+	* include/ruby/encoding.h (rb_enc_reg_new): added.
+
+	* insns.def (toregexp), marshal.c (r_object0): use rb_reg_new_str().
+
+	* re.c (rb_reg_regcomp, rb_reg_s_union): ditto.
+
 Fri Jan  4 23:08:48 2008  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* time.c (time_arg): use converted object.  [ruby-core:14759]
diff --git a/include/ruby/encoding.h b/include/ruby/encoding.h
index 89f3ec36b8..2c247c99e9 100644
--- a/include/ruby/encoding.h
+++ b/include/ruby/encoding.h
@@ -58,7 +58,8 @@ void rb_enc_associate_index(VALUE, int);
 void rb_enc_associate(VALUE, rb_encoding*);
 void rb_enc_copy(VALUE dst, VALUE src);
 
-VALUE rb_enc_str_new(const char*, long len, rb_encoding*);
+VALUE rb_enc_str_new(const char*, long, rb_encoding*);
+VALUE rb_enc_reg_new(const char*, long, rb_encoding*, int);
 PRINTF_ARGS(VALUE rb_enc_sprintf(rb_encoding *, const char*, ...), 2, 3);
 VALUE rb_enc_vsprintf(rb_encoding *, const char*, va_list);
 long rb_enc_strlen(const char*, const char*, rb_encoding*);
diff --git a/include/ruby/intern.h b/include/ruby/intern.h
index eaacc96052..9ccba10498 100644
--- a/include/ruby/intern.h
+++ b/include/ruby/intern.h
@@ -454,7 +454,9 @@ VALUE rb_reg_last_match(VALUE);
 VALUE rb_reg_match_pre(VALUE);
 VALUE rb_reg_match_post(VALUE);
 VALUE rb_reg_match_last(VALUE);
-VALUE rb_reg_new(VALUE, int);
+#define HAVE_RB_REG_NEW_STR 1
+VALUE rb_reg_new_str(VALUE, int);
+VALUE rb_reg_new(const char *, long, int);
 VALUE rb_reg_match(VALUE, VALUE);
 VALUE rb_reg_match2(VALUE);
 int rb_reg_options(VALUE);
diff --git a/insns.def b/insns.def
index e0d997b834..59c868d366 100644
--- a/insns.def
+++ b/insns.def
@@ -403,7 +403,7 @@ toregexp
 (VALUE val)
 {
     volatile VALUE tmp = str; /* for GC */
-    val = rb_reg_new(str, opt);
+    val = rb_reg_new_str(str, opt);
 }
 
 /**
diff --git a/marshal.c b/marshal.c
index d0f8e7500b..7119f5e8b7 100644
--- a/marshal.c
+++ b/marshal.c
@@ -1307,7 +1307,7 @@ r_object0(struct load_arg *arg, int *ivp, VALUE extmod)
 	{
 	    volatile VALUE str = r_bytes(arg);
 	    int options = r_byte(arg);
-	    v = r_entry(rb_reg_new(str, options), arg);
+	    v = r_entry(rb_reg_new_str(str, options), arg);
             v = r_leave(v, arg);
 	}
 	break;
diff --git a/re.c b/re.c
index b9a421a88f..9de2a0efa3 100644
--- a/re.c
+++ b/re.c
@@ -460,20 +460,33 @@ rb_reg_raise(const char *s, long len, const char *err, VALUE re)
 }
 
 static VALUE
-rb_reg_error_desc(VALUE str, int options, const char *err)
+rb_enc_reg_error_desc(const char *s, long len, rb_encoding *enc, int options, const char *err)
 {
     char opts[6];
     VALUE desc = rb_str_buf_new2(err);
 
-    rb_enc_copy(desc, str);
+    rb_enc_associate(desc, enc);
     rb_str_buf_cat2(desc, ": /");
-    rb_reg_expr_str(desc, RSTRING_PTR(str), RSTRING_LEN(str));
+    rb_reg_expr_str(desc, s, len);
     opts[0] = '/';
     option_to_str(opts + 1, options);
     rb_str_buf_cat2(desc, opts);
     return rb_exc_new3(rb_eRegexpError, desc);
 }
 
+static void
+rb_enc_reg_raise(const char *s, long len, rb_encoding *enc, int options, const char *err)
+{
+    rb_exc_raise(rb_enc_reg_error_desc(s, len, enc, options, err));
+}
+
+static VALUE
+rb_reg_error_desc(VALUE str, int options, const char *err)
+{
+    return rb_enc_reg_error_desc(RSTRING_PTR(str), RSTRING_LEN(str),
+				 rb_enc_get(str), options, err);
+}
+
 static void
 rb_reg_raise_str(VALUE str, int options, const char *err)
 {
@@ -2040,7 +2053,7 @@ rb_reg_s_alloc(VALUE klass)
 }
 
 VALUE
-rb_reg_new(VALUE s, int options)
+rb_reg_new_str(VALUE s, int options)
 {
     VALUE re = rb_reg_s_alloc(rb_cRegexp);
     onig_errmsg_buffer err;
@@ -2052,6 +2065,25 @@ rb_reg_new(VALUE s, int options)
     return re;
 }
 
+VALUE
+rb_enc_reg_new(const char *s, long len, rb_encoding *enc, int options)
+{
+    VALUE re = rb_reg_s_alloc(rb_cRegexp);
+    onig_errmsg_buffer err;
+
+    if (rb_reg_initialize(re, s, len, enc, options, err) != 0) {
+	rb_enc_reg_raise(s, len, enc, options, err);
+    }
+
+    return re;
+}
+
+VALUE
+rb_reg_new(const char *s, long len, int options)
+{
+    return rb_enc_reg_new(s, len, rb_ascii8bit_encoding(), options);
+}
+
 VALUE
 rb_reg_compile(VALUE str, int options)
 {
@@ -2078,7 +2110,7 @@ rb_reg_regcomp(VALUE str)
 	&& memcmp(RREGEXP(reg_cache)->str, RSTRING_PTR(str), RSTRING_LEN(str)) == 0)
 	return reg_cache;
 
-    return reg_cache = rb_reg_new(save_str, 0);
+    return reg_cache = rb_reg_new_str(save_str, 0);
 }
 
 /*
@@ -2607,7 +2639,7 @@ rb_reg_s_union(VALUE self, VALUE args0)
         else {
             VALUE quoted;
             quoted = rb_reg_s_quote(Qnil, arg);
-            return rb_reg_new(quoted, 0);
+            return rb_reg_new_str(quoted, 0);
         }
     }
     else {
diff --git a/version.h b/version.h
index 1c21a2c5e4..8a211a4291 100644
--- a/version.h
+++ b/version.h
@@ -1,7 +1,7 @@
 #define RUBY_VERSION "1.9.0"
-#define RUBY_RELEASE_DATE "2008-01-04"
+#define RUBY_RELEASE_DATE "2008-01-05"
 #define RUBY_VERSION_CODE 190
-#define RUBY_RELEASE_CODE 20080104
+#define RUBY_RELEASE_CODE 20080105
 #define RUBY_PATCHLEVEL 0
 
 #define RUBY_VERSION_MAJOR 1
@@ -9,7 +9,7 @@
 #define RUBY_VERSION_TEENY 0
 #define RUBY_RELEASE_YEAR 2008
 #define RUBY_RELEASE_MONTH 1
-#define RUBY_RELEASE_DAY 4
+#define RUBY_RELEASE_DAY 5
 
 #ifdef RUBY_EXTERN
 RUBY_EXTERN const char ruby_version[];