Alter the signature for encoding conversion functions to declare the

output area as INTERNAL not CSTRING.  This is to prevent people from
calling the functions by hand.  This is a permanent solution for the
back branches but I hope it is just a stopgap for HEAD.

doc/src/sgml/ref/create_conversion.sgml

-<!-- $PostgreSQL: pgsql/doc/src/sgml/ref/create_conversion.sgml,v 1.15 2005/03/07 04:30:51 momjian Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/ref/create_conversion.sgml,v 1.16 2005/05/03 19:17:59 tgl Exp $ -->
 
 <refentry id="SQL-CREATECONVERSION">
  <refmeta>
@@ -8,7 +8,7 @@
 
  <refnamediv>
   <refname>CREATE CONVERSION</refname>
-  <refpurpose>define a new conversion</refpurpose>
+  <refpurpose>define a new encoding conversion</refpurpose>
  </refnamediv>
 
  <indexterm zone="sql-createconversion">
@@ -26,10 +26,12 @@ CREATE [DEFAULT] CONVERSION <replaceable>name</replaceable>
   <title>Description</title>
 
   <para>
-   <command>CREATE CONVERSION</command> defines a new encoding
-   conversion.  Conversion names may be used in the <function>convert</function> function
+   <command>CREATE CONVERSION</command> defines a new conversion between
+   character set encodings.  Conversion names may be used in the
+   <function>convert</function> function
    to specify a particular encoding conversion.  Also, conversions that
-   are marked <literal>DEFAULT</> can be used for automatic encoding conversion between
+   are marked <literal>DEFAULT</> can be used for automatic encoding
+   conversion between
    client and server. For this purpose, two conversions, from encoding A to
    B <emphasis>and</emphasis> from encoding B to A, must be defined.
  </para>
@@ -109,7 +111,7 @@ conv_proc(
     integer,  -- source encoding ID
     integer,  -- destination encoding ID
     cstring,  -- source string (null terminated C string)
-    cstring,  -- destination string (null terminated C string)
+    internal, -- destination (fill with a null terminated C string)
     integer   -- source string length
 ) RETURNS void;
 </programlisting>

src/backend/commands/conversioncmds.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/conversioncmds.c,v 1.17 2005/04/14 20:03:23 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/conversioncmds.c,v 1.18 2005/05/03 19:17:59 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -45,7 +45,7 @@ CreateConversionCommand(CreateConversionStmt *stmt)
 	const char *from_encoding_name = stmt->for_encoding_name;
 	const char *to_encoding_name = stmt->to_encoding_name;
 	List	   *func_name = stmt->func_name;
-	static Oid	funcargs[] = {INT4OID, INT4OID, CSTRINGOID, CSTRINGOID, INT4OID};
+	static Oid	funcargs[] = {INT4OID, INT4OID, CSTRINGOID, INTERNALOID, INT4OID};
 
 	/* Convert list of names to a name and namespace */
 	namespaceId = QualifiedNameGetCreationNamespace(stmt->conversion_name,

src/backend/utils/mb/conversion_procs/Makefile

@@ -4,7 +4,7 @@
 #    Makefile for utils/mb/conversion_procs
 #
 # IDENTIFICATION
-#    $PostgreSQL: pgsql/src/backend/utils/mb/conversion_procs/Makefile,v 1.13 2005/03/14 18:31:21 momjian Exp $
+#    $PostgreSQL: pgsql/src/backend/utils/mb/conversion_procs/Makefile,v 1.14 2005/05/03 19:17:59 tgl Exp $
 #
 #-------------------------------------------------------------------------
 
@@ -159,7 +159,7 @@ ifeq ($(enable_shared), yes)
 		func=$$1; shift; \
 		obj=$$1; shift; \
 		echo "-- $$se --> $$de"; \
-		echo "CREATE OR REPLACE FUNCTION $$func (INTEGER, INTEGER, CSTRING, CSTRING, INTEGER) RETURNS VOID AS '$$"libdir"/$$obj', '$$func' LANGUAGE 'c' STRICT;"; \
+		echo "CREATE OR REPLACE FUNCTION $$func (INTEGER, INTEGER, CSTRING, INTERNAL, INTEGER) RETURNS VOID AS '$$"libdir"/$$obj', '$$func' LANGUAGE 'c' STRICT;"; \
 		echo "DROP CONVERSION pg_catalog.$$name;"; \
 		echo "CREATE DEFAULT CONVERSION pg_catalog.$$name FOR '$$se' TO '$$de' FROM $$func;"; \
 	done > $@