Pass session_authorization to the client and make psql update its prompt

accordingly.

doc/src/sgml/libpq.sgml

 <!--
-$Header: /cvsroot/pgsql/doc/src/sgml/libpq.sgml,v 1.134 2003/09/01 23:04:49 petere Exp $
+$Header: /cvsroot/pgsql/doc/src/sgml/libpq.sgml,v 1.135 2003/09/03 22:05:01 petere Exp $
 -->
 
  <chapter id="libpq">
@@ -857,7 +857,8 @@ is not known.
 Parameters reported as of the current release include
 <literal>server_version</> (cannot change after startup);
 <literal>client_encoding</>,
-<literal>is_superuser</>, and
+<literal>is_superuser</>,
+<literal>session_authorization</literal>, and
 <literal>DateStyle</>.
 </para>
 

doc/src/sgml/protocol.sgml

-<!-- $Header: /cvsroot/pgsql/doc/src/sgml/protocol.sgml,v 1.42 2003/09/01 23:04:49 petere Exp $ -->
+<!-- $Header: /cvsroot/pgsql/doc/src/sgml/protocol.sgml,v 1.43 2003/09/03 22:05:07 petere Exp $ -->
 
 <chapter id="protocol">
  <title>Frontend/Backend Protocol</title>
@@ -1006,7 +1006,8 @@
     <literal>server_version</> (a pseudo-parameter that cannot change after
     startup);
     <literal>client_encoding</>,
-    <literal>is_superuser</>, and
+    <literal>is_superuser</>,
+    <literal>session_authorization</literal>, and
     <literal>DateStyle</>.
     This set might change in the future, or even become configurable.
     Accordingly, a frontend should simply ignore ParameterStatus for

doc/src/sgml/ref/psql-ref.sgml

 <!--
-$Header: /cvsroot/pgsql/doc/src/sgml/ref/psql-ref.sgml,v 1.95 2003/08/31 17:32:24 petere Exp $
+$Header: /cvsroot/pgsql/doc/src/sgml/ref/psql-ref.sgml,v 1.96 2003/09/03 22:05:08 petere Exp $
 PostgreSQL documentation
 -->
 
@@ -2214,8 +2214,14 @@ testdb=> <userinput>\set content '\'' `sed -e "s/'/\\\\\\'/g" < my_file.txt` '\'
 
       <varlistentry>
         <term><literal>%n</literal></term>
-	<listitem><para>The user name you are connected as (not your local system
-         user name).</para></listitem>
+	<listitem>
+         <para>
+          The database session user name.  (The expansion of this
+          value might change during a database session as the result
+          of the command <command>SET SESSION
+          AUTHORIZATION</command>.)
+         </para>
+        </listitem>
       </varlistentry>
 
       <varlistentry>
@@ -2231,8 +2237,15 @@ testdb=> <userinput>\set content '\'' `sed -e "s/'/\\\\\\'/g" < my_file.txt` '\'
 
       <varlistentry>
         <term><literal>%#</literal></term>
-	<listitem><para>If the current user is a database superuser, then a
-         <literal>#</literal>, otherwise a <literal>&gt;</literal>.</para></listitem>
+	<listitem>
+         <para>
+          If the session user is a database superuser, then a
+          <literal>#</literal>, otherwise a <literal>&gt;</literal>.
+          (The expansion of this value might change during a database
+          session as the result of the command <command>SET SESSION
+          AUTHORIZATION</command>.)
+         </para>
+        </listitem>
       </varlistentry>
 
       <varlistentry>

src/backend/utils/misc/guc.c

@@ -10,7 +10,7 @@
  * Written by Peter Eisentraut <peter_e@gmx.net>.
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/utils/misc/guc.c,v 1.153 2003/09/01 23:04:49 petere Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/utils/misc/guc.c,v 1.154 2003/09/03 22:05:08 petere Exp $
  *
  *--------------------------------------------------------------------
  */
@@ -1501,7 +1501,7 @@ static struct config_string ConfigureNamesString[] =
 		{"session_authorization", PGC_USERSET, UNGROUPED,
 			gettext_noop("Current session userid"),
 			NULL,
-			GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
+			GUC_REPORT | GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
 		},
 		&session_authorization_string,
 		NULL, assign_session_authorization, show_session_authorization

src/bin/psql/common.c

@@ -3,7 +3,7 @@
  *
  * Copyright (c) 2000-2003, PostgreSQL Global Development Group
  *
- * $Header: /cvsroot/pgsql/src/bin/psql/common.c,v 1.72 2003/08/14 18:48:35 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/bin/psql/common.c,v 1.73 2003/09/03 22:05:08 petere Exp $
  */
 #include "postgres_fe.h"
 #include "common.h"
@@ -724,3 +724,26 @@ is_superuser(void)
 
 	return false;
 }
+
+
+/*
+ * Return the session user of the current connection.
+ *
+ * Note: this will correctly detect the session user only with a
+ * protocol-3.0 or newer backend; otherwise it will return the
+ * connection user.
+ */
+const char *
+session_username(void)
+{
+	const char *val;
+
+	if (!pset.db)
+		return NULL;
+
+	val = PQparameterStatus(pset.db, "session_authorization");
+	if (val)
+		return val;
+	else
+		return PQuser(pset.db);
+}

src/bin/psql/common.h

@@ -3,7 +3,7 @@
  *
  * Copyright (c) 2000-2003, PostgreSQL Global Development Group
  *
- * $Header: /cvsroot/pgsql/src/bin/psql/common.h,v 1.28 2003/08/08 04:52:21 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/bin/psql/common.h,v 1.29 2003/09/03 22:05:09 petere Exp $
  */
 #ifndef COMMON_H
 #define COMMON_H
@@ -37,6 +37,7 @@ extern PGresult *PSQLexec(const char *query, bool start_xact);
 extern bool SendQuery(const char *query);
 
 extern bool is_superuser(void);
+extern const char *session_username(void);
 
 /* Parse a numeric character code from the string pointed at by *buf, e.g.
  * one written as 0x0c (hexadecimal) or 015 (octal); advance *buf to the last

src/bin/psql/prompt.c

@@ -3,7 +3,7 @@
  *
  * Copyright (c) 2000-2003, PostgreSQL Global Development Group
  *
- * $Header: /cvsroot/pgsql/src/bin/psql/prompt.c,v 1.28 2003/08/04 23:59:40 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/bin/psql/prompt.c,v 1.29 2003/09/03 22:05:09 petere Exp $
  */
 #include "postgres_fe.h"
 #include "prompt.h"
@@ -160,7 +160,7 @@ get_prompt(promptStatus_t status)
 					/* DB server user name */
 				case 'n':
 					if (pset.db)
-						strncpy(buf, PQuser(pset.db), MAX_PROMPT_SIZE);
+						strncpy(buf, session_username(), MAX_PROMPT_SIZE);
 					break;
 
 				case '0':