Make new complaint about unsafe Unicode literals include an error location.

Every other ereport in scan.l has one, this should too.

src/backend/parser/scan.l

@@ -24,7 +24,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/parser/scan.l,v 1.152 2009/05/05 18:32:17 petere Exp $
+ *	  $PostgreSQL: pgsql/src/backend/parser/scan.l,v 1.153 2009/05/05 21:09:23 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -469,12 +469,13 @@ other			.
 					startlit();
 				}
 {xusstart}		{
+					SET_YYLLOC();
 					if (!standard_conforming_strings)
 						ereport(ERROR,
 								(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 								 errmsg("unsafe use of string constant with Unicode escapes"),
-								 errdetail("String constants with Unicode escapes cannot be used when standard_conforming_strings is off.")));
-					SET_YYLLOC();
+								 errdetail("String constants with Unicode escapes cannot be used when standard_conforming_strings is off."),
+								 lexer_errposition()));
 					BEGIN(xus);
 					startlit();
 				}

src/test/regress/expected/strings.out

@@ -62,12 +62,18 @@ LINE 1: SELECT U&'wrong: +0061' UESCAPE '+';
 SET standard_conforming_strings TO off;
 SELECT U&'d\0061t\+000061' AS U&"d\0061t\+000061";
 ERROR:  unsafe use of string constant with Unicode escapes
+LINE 1: SELECT U&'d\0061t\+000061' AS U&"d\0061t\+000061";
+               ^
 DETAIL:  String constants with Unicode escapes cannot be used when standard_conforming_strings is off.
 SELECT U&'d!0061t\+000061' UESCAPE '!' AS U&"d*0061t\+000061" UESCAPE '*';
 ERROR:  unsafe use of string constant with Unicode escapes
+LINE 1: SELECT U&'d!0061t\+000061' UESCAPE '!' AS U&"d*0061t\+000061...
+               ^
 DETAIL:  String constants with Unicode escapes cannot be used when standard_conforming_strings is off.
 SELECT U&' \' UESCAPE '!' AS "tricky";
 ERROR:  unsafe use of string constant with Unicode escapes
+LINE 1: SELECT U&' \' UESCAPE '!' AS "tricky";
+               ^
 DETAIL:  String constants with Unicode escapes cannot be used when standard_conforming_strings is off.
 SELECT 'tricky' AS U&"\" UESCAPE '!';
    \    
@@ -77,12 +83,18 @@ SELECT 'tricky' AS U&"\" UESCAPE '!';
 
 SELECT U&'wrong: \061';
 ERROR:  unsafe use of string constant with Unicode escapes
+LINE 1: SELECT U&'wrong: \061';
+               ^
 DETAIL:  String constants with Unicode escapes cannot be used when standard_conforming_strings is off.
 SELECT U&'wrong: \+0061';
 ERROR:  unsafe use of string constant with Unicode escapes
+LINE 1: SELECT U&'wrong: \+0061';
+               ^
 DETAIL:  String constants with Unicode escapes cannot be used when standard_conforming_strings is off.
 SELECT U&'wrong: +0061' UESCAPE '+';
 ERROR:  unsafe use of string constant with Unicode escapes
+LINE 1: SELECT U&'wrong: +0061' UESCAPE '+';
+               ^
 DETAIL:  String constants with Unicode escapes cannot be used when standard_conforming_strings is off.
 RESET standard_conforming_strings;
 --