Support SQL99 embedded double-quote syntax for quoted identifiers.

Allow this in the parser and in pg_dump, but it is probably not enough
 for a complete solution.
Better to have the feature started then never here.

src/backend/parser/scan.l

@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/parser/scan.l,v 1.73 2000/07/14 15:43:32 thomas Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/parser/scan.l,v 1.74 2000/08/06 17:50:38 thomas Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -136,6 +136,7 @@ xqcat			{quote}{whitespace_with_newline}{quote}
 dquote			\"
 xdstart			{dquote}
 xdstop			{dquote}
+xddouble		{dquote}{dquote}
 xdinside		[^"]+
 
 /* C-style comments
@@ -351,6 +352,9 @@ other			.
 					yylval.str = pstrdup(literalbuf);
 					return IDENT;
 				}
+<xd>{xddouble} {
+					addlit(yytext, yyleng-1);
+				}
 <xd>{xdinside}	{
 					addlit(yytext, yyleng);
 				}

src/bin/pg_dump/common.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/bin/pg_dump/common.c,v 1.44 2000/07/04 14:25:27 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/bin/pg_dump/common.c,v 1.45 2000/08/06 17:50:48 thomas Exp $
  *
  * Modifications - 6/12/96 - dave@bensoft.com - version 1.13.dhb.2
  *
@@ -517,8 +517,10 @@ fmtId(const char *rawid, bool force_quotes)
 
 	if (!force_quotes)
 	{
+		/* do a quick check on the first character... */
 		if (!islower((int) *rawid))
 			force_quotes = true;
+		/* otherwise check the entire string */
 		else
 			for (cp = rawid; *cp; cp++)
 			{
@@ -541,8 +543,15 @@ fmtId(const char *rawid, bool force_quotes)
 	appendPQExpBufferChar(id_return, '\"');
 	for (cp = rawid; *cp; cp++)
 	{
+		/* Did we find a double-quote in the string?
+		 * Then make this a double double-quote per SQL99.
+		 * Before, we put in a backslash/double-quote pair.
+		 * - thomas 2000-08-05 */
 		if (*cp == '\"')
-			appendPQExpBufferChar(id_return, '\\');
+		{
+			appendPQExpBufferChar(id_return, '\"');
+			appendPQExpBufferChar(id_return, '\"');
+		}
 		appendPQExpBufferChar(id_return, *cp);
 	}
 	appendPQExpBufferChar(id_return, '\"');