diff --git a/contrib/cube/cubescan.l b/contrib/cube/cubescan.l
index c5e1a20f6b..a47dc4334a 100644
--- a/contrib/cube/cubescan.l
+++ b/contrib/cube/cubescan.l
@@ -26,6 +26,7 @@ void cube_scanner_finish(void);
 
 %option 8bit
 %option never-interactive
+%option nodefault
 %option nounput
 %option noyywrap
 %option prefix="cube_yy"
@@ -44,7 +45,7 @@ float        ({integer}|{real})([eE]{integer})?
 \(           yylval = "("; return O_PAREN;
 \)           yylval = ")"; return C_PAREN;
 \,           yylval = ")"; return COMMA;
-[ ]+         /* discard spaces */
+[ \t\n\r\f]+ /* discard spaces */
 .            return yytext[0]; /* alert parser of the garbage */
 
 %%
diff --git a/contrib/seg/segscan.l b/contrib/seg/segscan.l
index 21eb5fa020..b2a3bbe684 100644
--- a/contrib/seg/segscan.l
+++ b/contrib/seg/segscan.l
@@ -25,6 +25,7 @@ void seg_scanner_finish(void);
 
 %option 8bit
 %option never-interactive
+%option nodefault
 %option nounput
 %option noyywrap
 %option prefix="seg_yy"
@@ -44,7 +45,7 @@ float        ({integer}|{real})([eE]{integer})?
 \<           yylval.text = "<"; return EXTENSION;
 \>           yylval.text = ">"; return EXTENSION;
 \~           yylval.text = "~"; return EXTENSION;
-[ ]+         /* discard spaces */
+[ \t\n\r\f]+ /* discard spaces */
 .            return yytext[0]; /* alert parser of the garbage */
 
 %%
diff --git a/contrib/tsearch/parser.l b/contrib/tsearch/parser.l
index 17ac21dcd1..3eb411dded 100644
--- a/contrib/tsearch/parser.l
+++ b/contrib/tsearch/parser.l
@@ -16,6 +16,7 @@ YY_BUFFER_STATE buf = NULL; /* buffer to parse; it need for parse from string */
 
 %option 8bit
 %option never-interactive
+%option nodefault
 %option nounput
 %option noyywrap
 
diff --git a/contrib/tsearch2/wordparser/parser.l b/contrib/tsearch2/wordparser/parser.l
index e36c19355c..e80f5fea90 100644
--- a/contrib/tsearch2/wordparser/parser.l
+++ b/contrib/tsearch2/wordparser/parser.l
@@ -18,6 +18,7 @@ YY_BUFFER_STATE buf = NULL; /* buffer to parse; it need for parse from string */
 
 %option 8bit
 %option never-interactive
+%option nodefault
 %option nounput
 %option noyywrap
 
diff --git a/src/backend/bootstrap/bootscanner.l b/src/backend/bootstrap/bootscanner.l
index 6d3081695f..d8f683596d 100644
--- a/src/backend/bootstrap/bootscanner.l
+++ b/src/backend/bootstrap/bootscanner.l
@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/bootstrap/bootscanner.l,v 1.32 2003/11/29 19:51:41 pgsql Exp $
+ *	  $PostgreSQL: pgsql/src/backend/bootstrap/bootscanner.l,v 1.33 2004/02/24 22:06:32 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -53,6 +53,7 @@ static int	yyline;  /* keep track of the line number for error reporting */
 
 %option 8bit
 %option never-interactive
+%option nodefault
 %option nounput
 %option noyywrap
 
diff --git a/src/backend/utils/misc/guc-file.l b/src/backend/utils/misc/guc-file.l
index df89572260..eb5f0c7f07 100644
--- a/src/backend/utils/misc/guc-file.l
+++ b/src/backend/utils/misc/guc-file.l
@@ -4,7 +4,7 @@
  *
  * Copyright (c) 2000-2003, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/backend/utils/misc/guc-file.l,v 1.20 2003/11/29 19:52:03 pgsql Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/misc/guc-file.l,v 1.21 2004/02/24 22:06:32 tgl Exp $
  */
 
 %{
@@ -47,6 +47,7 @@ char *GUC_scanstr(char *);
 
 %option 8bit
 %option never-interactive
+%option nodefault
 %option nounput
 %option noyywrap
 
diff --git a/src/interfaces/ecpg/preproc/pgc.l b/src/interfaces/ecpg/preproc/pgc.l
index 264f93f847..376c87c73b 100644
--- a/src/interfaces/ecpg/preproc/pgc.l
+++ b/src/interfaces/ecpg/preproc/pgc.l
@@ -12,7 +12,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/interfaces/ecpg/preproc/pgc.l,v 1.125 2004/02/15 13:48:54 meskes Exp $
+ *	  $PostgreSQL: pgsql/src/interfaces/ecpg/preproc/pgc.l,v 1.126 2004/02/24 22:06:32 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -70,6 +70,7 @@ static struct _if_value
 
 %option 8bit
 %option never-interactive
+%option nodefault
 %option noyywrap
 
 %option yylineno
diff --git a/src/pl/plpgsql/src/scan.l b/src/pl/plpgsql/src/scan.l
index 62a7880c6c..b891e2b9e1 100644
--- a/src/pl/plpgsql/src/scan.l
+++ b/src/pl/plpgsql/src/scan.l
@@ -4,7 +4,7 @@
  *			  procedural language
  *
  * IDENTIFICATION
- *    $PostgreSQL: pgsql/src/pl/plpgsql/src/scan.l,v 1.30 2003/11/29 19:52:12 pgsql Exp $
+ *    $PostgreSQL: pgsql/src/pl/plpgsql/src/scan.l,v 1.31 2004/02/24 22:06:32 tgl Exp $
  *
  *    This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -63,6 +63,7 @@ int	plpgsql_SpaceScanned = 0;
 
 %option 8bit
 %option never-interactive
+%option nodefault
 %option nounput
 %option noyywrap
 
@@ -272,6 +273,7 @@ dump			{ return O_DUMP;			}
 			  BEGIN IN_STRING;
 			}
 <IN_STRING>\\.		{ }
+<IN_STRING>\\		{ /* can only happen with \ at EOF */ }
 <IN_STRING>''		{ }
 <IN_STRING>'		{
 			  yyleng -= (yytext - start_charpos);
@@ -279,13 +281,13 @@ dump			{ return O_DUMP;			}
 			  BEGIN INITIAL;
 			  return T_STRING;
 			}
+<IN_STRING>[^'\\]+	{ }
 <IN_STRING><<EOF>>	{
 				plpgsql_error_lineno = start_lineno;
 				ereport(ERROR,
 						(errcode(ERRCODE_DATATYPE_MISMATCH),
 						 errmsg("unterminated string")));
 			}
-<IN_STRING>[^'\\]*	{ }
 
     /* ----------
      * Any unmatched character is returned as is