Simplify psql's new linestyle behavior to default to linestyle=ascii all

the time, rather than hoping we can tell whether the terminal supports
UTF8 characters.  Per discussion.

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

 <!--
-$PostgreSQL: pgsql/doc/src/sgml/ref/psql-ref.sgml,v 1.234 2009/11/22 22:06:30 tgl Exp $
+$PostgreSQL: pgsql/doc/src/sgml/ref/psql-ref.sgml,v 1.235 2009/11/25 20:26:30 tgl Exp $
 PostgreSQL documentation
 -->
 
@@ -1785,6 +1785,7 @@ lo_import 152801
           or <literal>unicode</literal>.
           Unique abbreviations are allowed.  (That would mean one
           letter is enough.)
+          The default setting is <literal>ascii</>.
           This option only affects the <literal>aligned</> and
           <literal>wrapped</> output formats.
           </para>
@@ -1826,12 +1827,6 @@ lo_import 152801
           Plain <acronym>ASCII</acronym> characters work everywhere, but
           Unicode characters look nicer on displays that recognize them.
           </para>
-
-          <para>
-          If this option has not been set, the default behavior is to use
-          <literal>unicode</literal> style if the client character set encoding
-          is UTF-8, otherwise <literal>ascii</literal> style.
-          </para>
           </listitem>
           </varlistentry>
 

doc/src/sgml/release-8.5.sgml

-<!-- $PostgreSQL: pgsql/doc/src/sgml/release-8.5.sgml,v 1.6 2009/10/21 19:43:06 petere Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/release-8.5.sgml,v 1.7 2009/11/25 20:26:31 tgl Exp $ -->
 
 <sect1 id="release-8-5">
   <title>Release 8.5alpha2</title>
@@ -410,8 +410,7 @@
          <emphasis>Add &quot;pset linestyle ascii/unicode&quot; option to psql,
          allowing our traditional ASCII-art style of table output to
          be upgraded to use Unicode box drawing characters if
-         desired. By default, psql will use the Unicode characters
-         whenever client_encoding is UTF8.</>
+         desired.
         </para>
        </listitem>
         <listitem>

src/bin/psql/mbprint.c

@@ -3,7 +3,7 @@
  *
  * Copyright (c) 2000-2009, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/bin/psql/mbprint.c,v 1.36 2009/10/13 21:04:01 tgl Exp $
+ * $PostgreSQL: pgsql/src/bin/psql/mbprint.c,v 1.37 2009/11/25 20:26:31 tgl Exp $
  *
  * XXX this file does not really belong in psql/.  Perhaps move to libpq?
  * It also seems that the mbvalidate function is redundant with existing
@@ -30,7 +30,7 @@
 
 typedef unsigned int pg_wchar;
 
-int
+static int
 pg_get_utf8_id(void)
 {
 	static int	utf8_id = -1;

src/bin/psql/mbprint.h

-/* $PostgreSQL: pgsql/src/bin/psql/mbprint.h,v 1.14 2009/10/13 21:04:01 tgl Exp $ */
+/* $PostgreSQL: pgsql/src/bin/psql/mbprint.h,v 1.15 2009/11/25 20:26:31 tgl Exp $ */
 #ifndef MBPRINT_H
 #define MBPRINT_H
 
@@ -9,7 +9,6 @@ struct lineptr
 	int			width;
 };
 
-extern int	pg_get_utf8_id(void);
 extern unsigned char *mbvalidate(unsigned char *pwcs, int encoding);
 extern int	pg_wcswidth(const unsigned char *pwcs, size_t len, int encoding);
 extern void pg_wcsformat(unsigned char *pwcs, size_t len, int encoding, struct lineptr * lines, int count);

src/bin/psql/print.c

@@ -3,7 +3,7 @@
  *
  * Copyright (c) 2000-2009, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/bin/psql/print.c,v 1.118 2009/11/22 05:20:41 tgl Exp $
+ * $PostgreSQL: pgsql/src/bin/psql/print.c,v 1.119 2009/11/25 20:26:31 tgl Exp $
  */
 #include "postgres_fe.h"
 
@@ -2550,10 +2550,13 @@ setDecimalLocale(void)
 const printTextFormat *
 get_line_style(const printTableOpt *opt)
 {
+	/*
+	 * Note: this function mainly exists to preserve the convention that
+	 * a printTableOpt struct can be initialized to zeroes to get default
+	 * behavior.
+	 */
 	if (opt->line_style != NULL)
 		return opt->line_style;
-	else if (opt->encoding == pg_get_utf8_id())
-		return &pg_utf8format;
 	else
 		return &pg_asciiformat;
 }

src/test/regress/pg_regress_main.c

@@ -11,7 +11,7 @@
  * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/test/regress/pg_regress_main.c,v 1.7 2009/10/13 21:04:01 tgl Exp $
+ * $PostgreSQL: pgsql/src/test/regress/pg_regress_main.c,v 1.8 2009/11/25 20:26:31 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -59,7 +59,7 @@ psql_start_test(const char *testname,
 	add_stringlist_item(expectfiles, expectfile);
 
 	snprintf(psql_cmd, sizeof(psql_cmd),
-			 SYSTEMQUOTE "\"%s%spsql\" -X -a -q -P linestyle=ascii -d \"%s\" < \"%s\" > \"%s\" 2>&1" SYSTEMQUOTE,
+			 SYSTEMQUOTE "\"%s%spsql\" -X -a -q -d \"%s\" < \"%s\" > \"%s\" 2>&1" SYSTEMQUOTE,
 			 psqldir ? psqldir : "",
 			 psqldir ? "/" : "",
 			 dblist->str,