Hi, here are the patches to enhance existing MB handling. This time

I have implemented a framework of encoding translation between the
backend and the frontend. Also I have added a new variable setting
command:

SET CLIENT_ENCODING TO 'encoding';

Other features include:
	Latin1 support more 8 bit cleaness

See doc/README.mb for more details. Note that the pacthes are
against May 30 snapshot.

Tatsuo Ishii

Author: bmomjian

doc/README.mb

@@ -1,10 +1,10 @@
-postgresql 6.3 multi-byte (MB) support README	  April 21 1998
+postgresql 6.4 multi-byte (MB) support README	  Jun 5 1998
 
 						Tatsuo Ishii
 						t-ishii@sra.co.jp
 		  http://www.sra.co.jp/people/t-ishii/PostgreSQL/
 
-Introduction
+0. Introduction
 
 The MB support is intended for allowing PostgreSQL to handle
 multi-byte character sets such as EUC(Extended Unix Code), Unicode and
@@ -18,7 +18,7 @@ have been fixed. I just confirmed that the regression test ran fine
 and a few French characters could be used with the patch. Please let
 me know if you find any problem while using 8-bit characters)
 
-How to use
+1. How to use
 
 create src/Makefile.custom with a line including:
 
@@ -36,6 +36,7 @@ where encoding_system is one of:
 	EUC_TW			Taiwan EUC
 	UNICODE			Unicode(UTF-8)
 	MULE_INTERNAL		Mule internal
+	LATIN1			ISO 8859-1 English and some European laguages
 
 Example:
 
@@ -49,7 +50,54 @@ Example:
 If MB is disabled, nothing is changed except better supporting for
 8-bit single byte character sets.
 
-References
+2. PGCLIENTENCODING
+
+If an environment variable PGCLIENTENCODING is defined on the
+frontend, automatic encoding translation is done by the backend. For
+example, if the backend has been compiled with MB=EUC_JP and
+PGCLIENTENCODING=SJIS(Shift JIS: yet another Japanese encoding
+system), then any SJIS strings coming from the frontend would be
+translated to EUC_JP before going into the parser. Outputs from the
+backend would be translated to SJIS of course.
+
+Supported encodings for PGCLIENTENCODING are:
+
+	EUC_JP			Japanese EUC
+	SJIS			Yet another Japanese encoding
+	EUC_CN			Chinese EUC
+	EUC_KR			Korean EUC
+	EUC_TW			Taiwan EUC
+	MULE_INTERNAL		Mule internal
+	LATIN1			ISO 8859-1 English and some European laguages
+
+Note that UNICODE is not supported(yet). Also note that the
+translation is not always possible. Suppose you choose EUC_JP for the
+backend, LATIN1 for the frotend, then some Japanese characters cannot
+be translated into latin. In this case, a letter cannot be represented
+in the Latin character set, would be transformed as:
+
+	(HEXA DECIMAL)
+
+3. SET CLIENT_ENCODING TO command
+
+Actually setting the frontend side encoding information is done by a
+new command:
+
+	SET CLIENT_ENCODING TO 'encoding';
+
+where encoding is one of the encodings those can be set to
+PGCLIENTENCODING.  To query the current the frontend encoding:
+
+	SHOW CLIENT_ENCODING;
+
+To return to the default encoding:
+
+	RESET CLIENT_ENCODING;
+
+This would reset the frontend encoding to same as the backend
+encoding, thus no endoing translation would be performed.
+
+4. References
 
 These are good sources to start learning various kind of encoding
 systems.
@@ -64,7 +112,14 @@ Unicode: http://www.unicode.org/
 	RFC 2044
 	UTF-8 is defined here.
 
-History
+5. History
+
+Jun 5, 1988
+	* add support for the encoding translation between the backend
+	  and the frontend
+	* new command SET CLIENT_ENCODING etc. added
+	* add support for LATIN1 character set
+	* enhance 8 bit cleaness
 
 April 21, 1998 some enhancements/fixes
 	* character_length(), position(), substring() are now aware of 

doc/README.mb.jp

@@ -1,4 +1,4 @@
-postgresql 6.3.2 multi-byte (MB) support README	       1998/4/21 $B:n@.(B
+postgresql 6.3.2 multi-byte (MB) support README	       1998/5/25 $B:n@.(B
 
 							$B@P0fC#IW(B
 						t-ishii@sra.co.jp
@@ -9,8 +9,8 @@ postgresql 6.3.2 multi-byte (MB) support README	       1998/4/21 $B:n@.(B
   PostgreSQL $B$K$*$1$k%^%k%A%P%$%H%5%]!<%H$O0J2<$N$h$&$JFCD'$r;}$C$F$$$^$9!#(B
 
     1.$B%^%k%A%P%$%HJ8;z$H$7$F!"F|K\8l!"Cf9q8l$J$I$N3F9q$N(B EUC$B!"(BUnicode$B!"(B
-      mule internal code $B$,%3%s%Q%$%k;~$KA*Br2DG=!#%G!<%?%Y!<%9$K$O(B
-      $B$3$N%3!<%I$N$^$^3JG<$5$l$^$9!#(B
+      mule internal code, ISO-8859-1 $B$,%3%s%Q%$%k;~$KA*Br2DG=!#(B
+      $B%G!<%?%Y!<%9$K$O$3$N%3!<%I$N$^$^3JG<$5$l$^$9!#(B
     2.$B%F!<%V%kL>$K%^%k%A%P%$%HJ8;z$,;HMQ2DG=(B($B$?$@$7!"(BOS $B$,%^%k%A%P%$%H(B
       $B$N%U%!%$%kL>$r5v$7$F$$$k$3$H$,I,MW(B)
     3.$B%+%i%`L>$K%^%k%A%P%$%HJ8;z$,;HMQ2DG=(B
@@ -19,6 +19,8 @@ postgresql 6.3.2 multi-byte (MB) support README	       1998/4/21 $B:n@.(B
     6.$B%^%k%A%P%$%HJ8;z$N(B LIKE $B8!:w$,;HMQ2DG=(B
     7.character_length(), position(), substring() $B$G$N%^%k%A%P%$%H(B
       $B%5%]!<%H(B
+    8.$B4D6-JQ?t(B PGCLIENTENCODING $B$K$h$j!"%/%i%$%"%s%HB&$NJ8;z%3!<%I(B
+      $B$,%P%C%/%(%s%IB&$H0[$k>l9g$K!"<+F0E*$K%3!<%IJQ49$r9T$J$$$^$9!#(B
 
 $B%$%s%9%H!<%k!'(B
   $B%G%U%)%k%H$G$O(B PostgreSQL $B$O%^%k%A%P%$%H$r%5%]!<%H$7$F$$$^$;$s!#(B
@@ -46,6 +48,9 @@ postgresql 6.3.2 multi-byte (MB) support README	       1998/4/21 $B:n@.(B
 			$B$9$J$o$A(B 0xffff $B$^$G$G$9!#(B
 	MULE_INTERNAL	mule $B$NFbIt%3!<%I!#$?$@$7!"(BType N $B$NITDjD9J8;z$O(B
 			$B%5%]!<%H$7$F$$$^$;$s!#(B
+	LATIN1		ISO8859 Latin 1$B!#%7%s%0%k%P%$%H$J$s$G$9$1$I!"(B
+			$B;n$7$H$$$&$3$H$G(B:-)$B$A$J$_$K!"(BLATIN2 etc. $B$O(B
+			$BL$%5%]!<%H!#(B
 
   $BA*Br$NL\0B$H$7$F$O!"1Q8l$HF|K\8l$7$+;H$o$J$$>l9g$O(B EUC_JP($BF1MM$K!"Cf(B
   $B9q8l$7$+;H$o$J$$>l9g$O(B EUC_CN... $B$J$I$H$J$j$^$9(B)$B!"$=$NB>$N8@8l$b;H$$$?(B
@@ -64,13 +69,101 @@ postgresql 6.3.2 multi-byte (MB) support README	       1998/4/21 $B:n@.(B
   http://www.sra.co.jp/people/t-ishii/PostgreSQL/ $B$G$b4JC1$J%$%s%9%H!<(B
   $B%kJ}K!$r>R2p$7$F$$$^$9!#(B
 
+$B4D6-JQ?t(B PGCLIENTENCODING $B$K$D$$$F!'(B
+
+  $B%G%U%)%k%H$G$O!"%3%s%Q%$%k;~$K;XDj$7$?%5!<%PB&$NJ8;z%3!<%I$H!"(Bpsql 
+  $B$J$I$N%/%i%$%"%s%HB&$NJ8;z%3!<%I$,0lCW$7$F$$$k$b$N$H8+Jo$5$l$^$9!#%5!<(B
+  $B%PB&$H0[$kJ8;z%3!<%I$r;H$$$?$$>l9g$O!"4D6-JQ?t(B PGCLIENTENCODING $B$r@_(B
+  $BDj$7$^$9!#@_Dj2DG=$JJ8;z%3!<%I$O!">e5-$K2C$(!"(BSJIS ($B%7%U%H(BJIS)
+  $B$,;XDj$G$-$^$9!#(B
+
+	$B$A$J$_$K!"(BSJIS $B$O(B JISX0201 $B$N(B 1$B%P%$%H%+%J!"$$$o$f$k!VH>3Q%+%?(B
+	$B%+%J!W$b%5%]!<%H$7$F$$$^$9(B($B7h$7$F!VH>3Q%+%?%+%J!W$N;HMQ$r$*4+(B
+	$B$a$7$F$$$k$o$1$8$c$J$$$G$9$,(B)$B!#(B
+
+  $B$?$H$($P!"(BMB=EUC_JP $B$G(B PostgeSQL $B$,%$%s%9%H!<%k$5$l$F$$$k>l9g!"(B
+  postmaster $B$rN)$A>e$2$k$H$-$K4D6-JQ?t(B PGCLIENTENCODING $B$K(B SJIS $B$r@_(B
+  $BDj$9$k$H!"%/%i%$%"%s%H$O(B SJIS $B%3!<%I$G(B PostgreSQL $B$K%"%/%;%9$G$-$k$h(B
+  $B$&$K$J$j$^$9!#$?$@$7!"%G!<%?%Y!<%9$K3JG<$5$l$k%G!<%?<+BN$O$"$/$^$G(B 
+  MB $B$G;XDj$7$?(B EUC_JP $B$N$^$^$G$9!#(B
+
+  $B%/%i%$%"%s%HB&$G%;%C%7%g%sKh$KJ8;z%3!<%I$rJQ$($k$3$H$b$G$-$^$9!#(B
+  $B%;%C%7%g%s3+;O;~$K4D6-JQ?t(B PGCLIENTENCODING $B$,%;%C%H$5$l$F$$$k$H!"$=(B
+  $B$l$,M%@h$5$l$F%/%i%$%"%s%HB&$NJ8;z%3!<%I$K:NMQ$5$l$^$9!#$3$N5!G=$rMx(B
+  $BMQ$9$k$H!"$"$k%f!<%6$O(B EUC_JP $B$G!"JL$J%f!<%6$O(B SJIS $B$GF1$8%G!<%?%Y!<(B
+  $B%9$K%"%/%;%9$9$k$H$$$&$h$&$J$3$H$,$G$-$k$h$&$K$J$j$^$9!#(B
+
+  MB=MULE_INTERNAL $B$G(B PostgreSQL $B$r%$%s%9%H!<%k$7$F$*$/$H!"IaCJ$O(B 
+  EUC_JP $B$G%/%i%$%"%s%H$rMxMQ$7!"J#?t$NJ8;z=89g$r:.:_$5$;$k$H$-$@$1%/(B
+  $B%i%$%"%s%H$r(B MULE_INTERNAL $B$K@_Dj$9$k$J$I$N;H$$J,$1$,$G$-$FJXMx$G$9!#(B
+  $B$?$@!"0lHL$K(B EUC_JP $B$KHf$Y!"(BMULE_INTERNAL $B$K$h$k%G!<%?I=8=$O$d$d%9%Z!<(B
+  $B%9$r6t$&$N$G!"$=$N$X$s$O9MN8$7$F$*$/I,MW$,$"$j$^$9!#$?$H$($P!"(B2$B%P%$(B
+  $B%H$GI=8=$G$-$k4A;z$O(B MULE_INTERNAL $B$G$O(B 3$B%P%$%H$rMW$7$^$9!#(B
+
+  $BCm0U$7$F$*$/I,MW$,$"$k$N$O!"%5!<%PB&$NJ8;z%3!<%I$H%/%i%$%"%s%HB&$NJ8(B
+  $B;z%3!<%I$,$$$D$bAj8_JQ49$G$-$k$H$O8B$i$J$$$3$H$G$9!#6KC<$JOC!"%5!<%P(B
+  $BB&$,(B EUC_JP $B$J$N$K!"%/%i%$%"%s%HB&$,(B EUC_KR $B$@$C$?$i$I$&$J$k$G$7$g$&!#(B
+  $B$3$N>l9g(B PostgreSQL $B$OJQ49$G$-$J$$%3!<%I$r(B 16$B?JI=8=$KJQ49$7$F$7$^$$(B
+  $B$^$9!#$?$H$($P!"(B"(bdae)" $B$N$h$&$K!#$J$*!"$3$N(B 16$B?JI=8=$O(B mule
+  internalcode $B$N%3!<%I$G$"$k$3$H$KCm0U$7$F2<$5$$!#$3$l$O!"D>@\%/%i%$(B
+  $B%"%s%H(B <--> $B%5!<%P$NJ8;z%3!<%I$rJQ49$9$k$N$G$O$J$/!"0lEYFbItI=8=$G$"(B
+  $B$k(B mule internal code $B$r7PM3$7$F$$$k$?$a$G$9!#(B
+
+  $B%/%i%$%"%s%HB&$NJ8;z%3!<%I$N@_Dj$O!"(B"set client_encoding" $B%3%^%s%I$G(B
+  $B$b2DG=$G$9!#$?$H$($P!"(B
+
+	set client_encoding to 'sjis';
+
+  $B$GL@<(E*$K%/%i%$%"%s%HB&$NJ8;z%3!<%I$r(B SJIS $B$K@_Dj$G$-$^$9!#<B:]!"%/(B
+  $B%i%$%"%s%H$,%5!<%P$K@\B3$9$k:]$K$O(B libpq $B$NCf$G(B "set
+  client_encoding" $B%3%^%s%I$rH/9T$7$F$$$^$9!#%;%C%7%g%sCf$K(B 
+  set client_encoding" $B%3%^%s%I$rH/9T$9$l$P!"F0E*$KJ8;z%3!<%I$N@ZBX$((B
+  $B$,$G$-$^$9$,!"$=$N:]$K$O4D6-JQ?t(B PGCLIENTENCODING $B$rF1;~$K%/%i%$%"%s(B
+  $B%H%"%W%j%1!<%7%g%s$NCf$G@_Dj$7D>$9I,MW$,$"$j$^$9!#(B(psql $B$K$O8=:_$3$N(B
+  $B5!G=$,$J$$$?$a!";v<B>eF0E*$K%/%i%$%"%s%HB&$NJ8;z%3!<%I$r@_Dj$9$k$3$H(B
+  $B$,$G$-$^$;$s!#(B)
+
+  $B8=:_@_Dj$5$l$F$$$k%/%i%$%"%s%HB&$NJ8;z%3!<%I$O(B
+
+	show client_encoding;
+
+  $B$G;2>H$G$-$^$9!#$^$?!"(B
+
+	reset client_encoding;
+
+  $B$O!"%G%U%)%k%H$N%/%i%$%"%s%HJ8;z%3!<%I@_Dj$KI|5"$5$;$^$9!#(Bpostmaster 
+  $B$rN)$A>e$2$k$H$-$K4D6-JQ?t(B PGCLIENTENCODING $B$,@_Dj$5$l$F$$$k$H$=$NJ8(B
+  $B;z%3!<%I$K!"$=$&$G$J$1$l$P%3%s%Q%$%k;~$K;XDj$7$?%5!<%PB&$NJ8;z%3!<%I(B
+  $B$HF1$8$K$J$j$^$9!#(B
+
+$B@)8B;v9`!'(B
+
+  SJIS $B$r;HMQ$9$k>l9g!"(BPostgreSQL $B$N%/%i%$%"%s%H$G$^$H$b$KBP1~$7$F$$$k(B
+  $B$N$O(B psql $B$@$1$G$9!#(BTcl/Tk$B!"$=$N$[$+$OBP1~$7$F$^$;$s!#(B
+
 $B<U<-!'(B
+
   o $B3F<oJ8;z%;%C%H!"%3!<%I7O$K$D$$$F!"F|K\8l(B PostgreSQL $B%a!<%j%s%0%j%9%H(B
     $B$N%a%s%P$NJ}$+$i%"%I%P%$%9$rD:$-$^$7$?!#$3$3$K46<U$7$^$9!#(B
+    $B$^$?!"(BSJIS $BBP1~$K$D$$$F$O!";T@n(B@$B$*CcBg$5$s$N%Q%C%A$r;29M$K$5$;$F$$(B
+    $B$?$@$-$^$7$?!#(B
 
 $B2~DjMzNr!'(B
 
-  1998/4/21 $B5!G=DI2C!?%P%0=$@5(B
+  1998/5/25 $B%P%0=$@5(B(mb_b3.patch $B$H$7$F(B pgsql-jp ML $B$K%j%j!<%9!"(B
+	$BK\2H$G$O(B 6.4 snapshot $B$K<h$j9~$^$l$kM=Dj(B)	
+
+  1998/5/18 $B5!G=DI2C!?%P%0=$@5(B(mb_b2.patch $B$H$7$F(B pgsql-jp ML $B$K%j%j!<%9!"(B
+	$BK\2H$G$O(B 6.4 snapshot $B$K<h$j9~$^$l$kM=Dj(B)
+	* $B4D6-JQ?t(B PGCLIENTENCODING $B$N%5%]!<%H!#%/%i%$%"%s%HB&$N(B
+	  $BJ8;z%3!<%I$r;XDj$9$k!#8=:_!"(BSJIS, EUC_*, MULE_INTERNAL, LATIN1
+	  $B$,;XDj$G$-$k!#$^$?!"(B
+	  set client_encoding to 'sjis';
+	  $B$G$b2DG=(B
+	* 8bit $BJ8;z$,EO$k$HLdBj$,5/$-$k2U=j$K$G$-$k$@$1BP1~(B
+
+  1998/4/21 $B5!G=DI2C!?%P%0=$@5(B(mb_b1.patch $B$H$7$F(B pgsql-jp ML $B$K%j%j!<%9!"(B
+	$BK\2H$G$O(B 6.4 snapshot $B$K<h$j9~$^$l$F$$$k(B)
 	* character_length(), position(), substring() $B$N%^%k%A%P%$%H(B
 	  $BBP1~(B
 	* octet_length() $BDI2C(B $B"*(B initdb $B$N$d$jD>$7I,MW(B

src/Makefile.global.in

@@ -7,7 +7,7 @@
 #
 #
 # IDENTIFICATION
-#    $Header: /cvsroot/pgsql/src/Makefile.global.in,v 1.42 1998/05/12 15:42:08 momjian Exp $
+#    $Header: /cvsroot/pgsql/src/Makefile.global.in,v 1.43 1998/06/16 07:29:15 momjian Exp $
 #
 # NOTES
 #    Essentially all Postgres make files include this file and use the 
@@ -150,7 +150,7 @@ X11_LIBS= -lX11 @X_EXTRA_LIBS@
 #
 # enable multi-byte support
 # choose one of:
-# EUC_JP,EHC_CN,EUC_KR,EUC_TW,UNICODE,MULE_INTERNAL
+# EUC_JP,EUC_CN,EUC_KR,EUC_TW,UNICODE,MULE_INTERNAL,LATIN1
 MB=@MB@
 
 ##############################################################################

src/backend/access/common/Makefile

@@ -4,7 +4,7 @@
 #    Makefile for access/common
 #
 # IDENTIFICATION
-#    $Header: /cvsroot/pgsql/src/backend/access/common/Makefile,v 1.10 1998/04/06 00:20:44 momjian Exp $
+#    $Header: /cvsroot/pgsql/src/backend/access/common/Makefile,v 1.11 1998/06/16 07:29:18 momjian Exp $
 #
 #-------------------------------------------------------------------------
 
@@ -13,6 +13,10 @@ include ../../../Makefile.global
 
 CFLAGS+=-I../..
 
+ifdef MB
+CFLAGS+= -DMB=$(MB)
+endif
+
 OBJS = heaptuple.o heapvalid.o indextuple.o indexvalid.o printtup.o \
        scankey.o tupdesc.o  
 

src/backend/access/common/printtup.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/access/common/printtup.c,v 1.28 1998/05/14 17:18:12 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/access/common/printtup.c,v 1.29 1998/06/16 07:29:18 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -23,6 +23,10 @@
 #include <libpq/libpq.h>
 #include <utils/syscache.h>
 
+#ifdef MB
+#include <commands/variable.h>
+#endif
+
 /* ----------------------------------------------------------------
  *		printtup / debugtup support
  * ----------------------------------------------------------------
@@ -80,6 +84,9 @@ printtup(HeapTuple tuple, TupleDesc typeinfo)
 	Datum		attr;
 	bool		isnull;
 	Oid			typoutput;
+#ifdef MB
+	unsigned char *p;
+#endif
 
 	/* ----------------
 	 *	tell the frontend to expect new tuple data
@@ -125,8 +132,14 @@ printtup(HeapTuple tuple, TupleDesc typeinfo)
 			outputstr = fmgr(typoutput, attr,
 							 gettypelem(typeinfo->attrs[i]->atttypid),
 							 typeinfo->attrs[i]->atttypmod);
+#ifdef MB
+			p = pg_server_to_client(outputstr, strlen(outputstr));
+			pq_putint(strlen(p) + VARHDRSZ, VARHDRSZ);
+			pq_putnchar(p, strlen(p));
+#else
 			pq_putint(strlen(outputstr) + VARHDRSZ, VARHDRSZ);
 			pq_putnchar(outputstr, strlen(outputstr));
+#endif
 			pfree(outputstr);
 		}
 	}
@@ -268,8 +281,12 @@ printtup_internal(HeapTuple tuple, TupleDesc typeinfo)
 				/* variable length, assume a varlena structure */
 				len = VARSIZE(attr) - VARHDRSZ;
 
+#ifdef MB
+				pq_putncharlen(VARDATA(attr), len);
+#else
 				pq_putint(len, VARHDRSZ);
 				pq_putnchar(VARDATA(attr), len);
+#endif
 #ifdef IPORTAL_DEBUG
 				{
 					char	   *d = VARDATA(attr);

src/backend/commands/Makefile

@@ -4,7 +4,7 @@
 #    Makefile for commands
 #
 # IDENTIFICATION
-#    $Header: /cvsroot/pgsql/src/backend/commands/Makefile,v 1.12 1998/04/06 00:22:19 momjian Exp $
+#    $Header: /cvsroot/pgsql/src/backend/commands/Makefile,v 1.13 1998/06/16 07:29:20 momjian Exp $
 #
 #-------------------------------------------------------------------------
 
@@ -13,11 +13,19 @@ include ../../Makefile.global
 
 CFLAGS += -I..
 
+ifdef MB
+CFLAGS += -DMB=$(MB)
+endif
+
 OBJS = async.o creatinh.o command.o copy.o defind.o define.o \
        remove.o rename.o vacuum.o version.o view.o cluster.o \
        recipe.o explain.o sequence.o trigger.o user.o proclang.o \
        dbcommands.o variable.o
 
+ifdef MB
+OBJS += mbutils.o
+endif
+
 all: SUBSYS.o
 
 SUBSYS.o: $(OBJS)