diff -ur mutt-1.5.9.orig/PATCHES mutt-1.5.9/PATCHES
--- mutt-1.5.9.orig/PATCHES	2005-03-14 01:33:06.000000000 +0900
+++ mutt-1.5.9/PATCHES	2005-03-28 01:47:46.229872728 +0900
@@ -0,0 +1 @@
+patch-1.5.9.tt.assumed_charset.2
diff -ur mutt-1.5.9.orig/charset.c mutt-1.5.9/charset.c
--- mutt-1.5.9.orig/charset.c	2005-02-13 04:53:00.000000000 +0900
+++ mutt-1.5.9/charset.c	2005-03-28 01:47:46.234871968 +0900
@@ -282,6 +282,21 @@
   return !ascii_strcasecmp (buffer, chs);
 }
 
+char *mutt_get_default_charset ()
+{
+  static char fcharset[SHORT_STRING];
+  const char *c = AssumedCharset;
+  const char *c1;
+
+  if (c && *c)
+  {
+    c1 = strchr (c, ':');
+    strfcpy (fcharset, c, c1 ? (c1 - c + 1) : (mutt_strlen (c) + 1));
+  }
+  else
+    strcpy (fcharset, "us-ascii");
+  return fcharset;
+}
 
 #ifndef HAVE_ICONV
 
diff -ur mutt-1.5.9.orig/charset.h mutt-1.5.9/charset.h
--- mutt-1.5.9.orig/charset.h	2003-03-03 19:22:06.000000000 +0900
+++ mutt-1.5.9/charset.h	2005-03-28 01:47:46.237871512 +0900
@@ -47,6 +47,7 @@
 void fgetconv_close (FGETCONV **);
 
 void mutt_set_langinfo_charset (void);
+char *mutt_get_default_charset ();
 
 #define M_ICONV_HOOK_FROM 1
 #define M_ICONV_HOOK_TO   2
diff -ur mutt-1.5.9.orig/globals.h mutt-1.5.9/globals.h
--- mutt-1.5.9.orig/globals.h	2005-02-13 05:01:02.000000000 +0900
+++ mutt-1.5.9/globals.h	2005-03-28 01:47:46.240871056 +0900
@@ -32,6 +32,7 @@
 
 WHERE char *AliasFile;
 WHERE char *AliasFmt;
+WHERE char *AssumedCharset;
 WHERE char *AttachSep;
 WHERE char *Attribution;
 WHERE char *AttachFormat;
diff -ur mutt-1.5.9.orig/handler.c mutt-1.5.9/handler.c
--- mutt-1.5.9.orig/handler.c	2005-02-04 03:47:52.000000000 +0900
+++ mutt-1.5.9/handler.c	2005-03-28 01:47:46.250869536 +0900
@@ -1728,6 +1728,8 @@
   if (istext && s->flags & M_CHARCONV)
   {
     char *charset = mutt_get_parameter ("charset", b->parameter);
+    if (!charset && AssumedCharset && *AssumedCharset)
+      charset = mutt_get_default_charset ();
     if (charset && Charset)
       cd = mutt_iconv_open (Charset, charset, M_ICONV_HOOK_FROM);
   }
diff -ur mutt-1.5.9.orig/init.h mutt-1.5.9/init.h
--- mutt-1.5.9.orig/init.h	2005-03-02 00:56:02.000000000 +0900
+++ mutt-1.5.9/init.h	2005-03-28 01:47:46.267866952 +0900
@@ -185,6 +185,22 @@
   ** If set, Mutt will prompt you for carbon-copy (Cc) recipients before
   ** editing the body of an outgoing message.
   */  
+  { "assumed_charset", DT_STR, R_NONE, UL &AssumedCharset, UL 0},
+  /*
+  ** .pp
+  ** This variable is a colon-separated list of character encoding
+  ** schemes for messages without character encoding indication.
+  ** Header field values and message body content without character encoding
+  ** indication would be assumed that they are written in one of this list.
+  ** By default, all the header fields and message body without any charset
+  ** indication are assumed to be in "us-ascii".
+  ** .pp
+  ** For example, Japanese users might prefer this:
+  ** .pp
+  **   set assumed_charset="iso-2022-jp:euc-jp:shift_jis:utf-8"
+  ** .pp
+  ** However, only the first content is valid for the message body.
+  */
   { "attach_format",	DT_STR,  R_NONE, UL &AttachFormat, UL "%u%D%I %t%4n %T%.40d%> [%.7m/%.10M, %.6e%?C?, %C?, %s] " },
   /*
   ** .pp
diff -ur mutt-1.5.9.orig/parse.c mutt-1.5.9/parse.c
--- mutt-1.5.9.orig/parse.c	2005-02-21 13:45:57.000000000 +0900
+++ mutt-1.5.9/parse.c	2005-03-28 01:47:46.276865584 +0900
@@ -213,9 +213,23 @@
 
       if (*s == '"')
       {
+        int state_ascii = 1;
 	s++;
-	for (i=0; *s && *s != '"' && i < sizeof (buffer) - 1; i++, s++)
+	for (i=0; *s && i < sizeof (buffer) - 1; i++, s++)
 	{
+	  if (AssumedCharset && *AssumedCharset) {
+            /* As iso-2022-* has a characer of '"' with non-ascii state,
+	     * ignore it. */
+            if (*s == 0x1b && i < sizeof (buffer) - 2)
+            {
+              if (s[1] == '(' && (s[2] == 'B' || s[2] == 'J'))
+                state_ascii = 1;
+              else
+                state_ascii = 0;
+            }
+          }
+          if (state_ascii && *s == '"')
+            break;
 	  if (*s == '\\')
 	  {
 	    /* Quote the next character */
@@ -384,7 +398,9 @@
   if (ct->type == TYPETEXT)
   {
     if (!(pc = mutt_get_parameter ("charset", ct->parameter)))
-      mutt_set_parameter ("charset", "us-ascii", &ct->parameter);
+      mutt_set_parameter ("charset", (AssumedCharset && *AssumedCharset) ?
+                         (const char *) mutt_get_default_charset ()
+                         : "us-ascii", &ct->parameter);
   }
 
 }
diff -ur mutt-1.5.9.orig/rfc2047.c mutt-1.5.9/rfc2047.c
--- mutt-1.5.9.orig/rfc2047.c	2005-02-04 03:47:53.000000000 +0900
+++ mutt-1.5.9/rfc2047.c	2005-03-28 01:47:53.060834264 +0900
@@ -87,6 +87,39 @@
   return n;
 }
 
+int convert_nonmime_string (char **ps)
+{
+  const char *p, *q;
+
+  for (p = AssumedCharset; p; p = q ? q + 1 : 0)
+  {
+    char *u = *ps;
+    char *s;
+    char *fromcode;
+    size_t m, n;
+    size_t ulen = mutt_strlen (*ps);
+    size_t slen;
+
+    if (!u || !*u)
+      return 0;
+
+    q = strchr (p, ':');
+    n = q ? q - p : mutt_strlen (p);
+    if (!n)
+      continue;
+    fromcode = mutt_substrdup(p, q);
+    m = convert_string (u, ulen, fromcode, Charset, &s, &slen);
+    FREE (&fromcode);
+    if (m != (size_t)(-1))
+    {
+      FREE (ps);
+      *ps = s;
+      return 0;
+    }
+  }
+  return -1;
+}
+
 char *mutt_choose_charset (const char *fromcode, const char *charsets,
 		      char *u, size_t ulen, char **d, size_t *dlen)
 {
@@ -733,6 +766,22 @@
     if (!(p = find_encoded_word (s, &q)))
     {
       /* no encoded words */
+      if (AssumedCharset && *AssumedCharset)
+      {
+	char *t;
+	size_t tlen;
+
+	t = safe_strdup (s);
+	if (convert_nonmime_string (&t) == 0)
+	{
+	  tlen = mutt_strlen (t);
+	  strncpy (d, t, tlen);
+	  d += tlen;
+	  FREE (&t);
+	  break;
+	}
+	FREE (&t);
+      }
       strncpy (d, s, dlen);
       d += dlen;
       break;
@@ -770,7 +819,8 @@
 {
   while (a)
   {
-    if (a->personal && strstr (a->personal, "=?") != NULL)
+    if (a->personal && ((strstr (a->personal, "=?") != NULL) || 
+			(AssumedCharset && *AssumedCharset)))
       rfc2047_decode (&a->personal);
 #ifdef EXACT_ADDRESS
     if (a->val && strstr (a->val, "=?") != NULL)
diff -ur mutt-1.5.9.orig/rfc2047.h mutt-1.5.9/rfc2047.h
--- mutt-1.5.9.orig/rfc2047.h	2002-12-11 20:19:40.000000000 +0900
+++ mutt-1.5.9/rfc2047.h	2005-03-28 01:47:46.285864216 +0900
@@ -18,6 +18,7 @@
 
 char *mutt_choose_charset (const char *fromcode, const char *charsets,
 		      char *u, size_t ulen, char **d, size_t *dlen);
+int convert_nonmime_string (char **);
 
 void _rfc2047_encode_string (char **, int, int);
 void rfc2047_encode_adrlist (ADDRESS *, const char *);
diff -ur mutt-1.5.9.orig/rfc2231.c mutt-1.5.9/rfc2231.c
--- mutt-1.5.9.orig/rfc2231.c	2005-02-04 03:47:53.000000000 +0900
+++ mutt-1.5.9/rfc2231.c	2005-03-28 01:47:46.289863608 +0900
@@ -117,6 +117,8 @@
 
       if (option (OPTRFC2047PARAMS) && p->value && strstr (p->value, "=?"))
 	rfc2047_decode (&p->value);
+      else if (AssumedCharset && *AssumedCharset)
+        convert_nonmime_string (&p->value);
 
       *last = p;
       last = &p->next;