bk commit into 6.0 tree (malff:1.2623) BUG#35936

[marc.alff]

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6.0 repository of malff.  When malff does a push these changes
will be propagated to the main repository and, within 24 hours after the
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ChangeSet@stripped, 2008-04-21 17:37:29-06:00, malff@stripped. +4 -0
  Bug#35936 (Garbage in syntax error message)
  
  Before this fix, the default initialization of
  Lex_input_stream::lookahead_token was using the value END_OF_INPUT
  to represent that no lookahead token has been parsed.
  
  This choice was unfortunate, since END_OF_INPUT is a real token value
  that can be returned by the lexer, which caused confusion when a query contains
  the following tokens:
    <WITH> <END_OF_INPUT>
  which in turn happens when a (malformed) query ends with <WITH>.
  
  Changed the value that represents "no token" to an out-of-bound token value,
  (-1), that can not be returned by the lexer.

  mysql-test/r/parser.result@stripped, 2008-04-21 17:03:13-06:00,
malff@stripped. +8 -0
    Bug#35936 (Garbage in syntax error message)

  mysql-test/t/parser.test@stripped, 2008-04-21 17:03:13-06:00,
malff@stripped. +26 -1
    Bug#35936 (Garbage in syntax error message)

  sql/sql_lex.cc@stripped, 2008-04-21 17:03:14-06:00, malff@stripped. +3 -3
    Bug#35936 (Garbage in syntax error message)

  sql/sql_lex.h@stripped, 2008-04-21 17:03:14-06:00, malff@stripped. +6 -1
    Bug#35936 (Garbage in syntax error message)

diff -Nrup a/mysql-test/r/parser.result b/mysql-test/r/parser.result
--- a/mysql-test/r/parser.result	2008-03-26 20:28:21 -06:00
+++ b/mysql-test/r/parser.result	2008-04-21 17:03:13 -06:00
@@ -352,6 +352,14 @@ $$
 1
 1
 DROP PROCEDURE p26030;
+SHOW NEW MASTER FOR SLAVE WITH;
+ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to
your MySQL server version for the right syntax to use near '' at line 1
+SHOW NEW MASTER FOR SLAVE WITH foo bar baz;
+ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to
your MySQL server version for the right syntax to use near 'foo bar baz' at line 1
+SHOW NEW MASTER FOR SLAVE WITH$$
+ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to
your MySQL server version for the right syntax to use near '' at line 1
+SHOW NEW MASTER FOR SLAVE WITH;$$
+ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to
your MySQL server version for the right syntax to use near '' at line 1
 select pi(3.14);
 ERROR 42000: Incorrect parameter count in the call to native function 'pi'
 select tan();
diff -Nrup a/mysql-test/t/parser.test b/mysql-test/t/parser.test
--- a/mysql-test/t/parser.test	2008-03-27 12:21:24 -06:00
+++ b/mysql-test/t/parser.test	2008-04-21 17:03:13 -06:00
@@ -434,7 +434,32 @@ $$
 delimiter ;$$
 DROP PROCEDURE p26030;
 
-#=============================================================================
+#
+# Bug#35936 (Garbage in syntax error message)
+#
+
+# test that
+# - <WITH> <END_OF_INPUT>
+# - <WITH> <YYEOF>
+# are parsed properly during the LALR(2) lookup
+
+--error ER_PARSE_ERROR
+SHOW NEW MASTER FOR SLAVE WITH;
+
+--error ER_PARSE_ERROR
+SHOW NEW MASTER FOR SLAVE WITH foo bar baz;
+
+delimiter $$;
+
+--error ER_PARSE_ERROR
+SHOW NEW MASTER FOR SLAVE WITH$$
+
+--error ER_PARSE_ERROR
+SHOW NEW MASTER FOR SLAVE WITH;$$
+
+delimiter ;$$
+
+#============================================================================r
 # SYNTACTIC PARSER (bison)
 #=============================================================================
 
diff -Nrup a/sql/sql_lex.cc b/sql/sql_lex.cc
--- a/sql/sql_lex.cc	2008-04-21 01:30:29 -06:00
+++ b/sql/sql_lex.cc	2008-04-21 17:03:14 -06:00
@@ -125,7 +125,7 @@ Lex_input_stream::Lex_input_stream(THD *
   yylineno(1),
   yytoklen(0),
   yylval(NULL),
-  lookahead_token(END_OF_INPUT),
+  lookahead_token(-1),
   lookahead_yylval(NULL),
   m_ptr(buffer),
   m_tok_start(NULL),
@@ -736,14 +736,14 @@ int MYSQLlex(void *arg, void *yythd)
   YYSTYPE *yylval=(YYSTYPE*) arg;
   int token;
 
-  if (lip->lookahead_token != END_OF_INPUT)
+  if (lip->lookahead_token >= 0)
   {
     /*
       The next token was already parsed in advance,
       return it.
     */
     token= lip->lookahead_token;
-    lip->lookahead_token= END_OF_INPUT;
+    lip->lookahead_token= -1;
     *yylval= *(lip->lookahead_yylval);
     lip->lookahead_yylval= NULL;
     return token;
diff -Nrup a/sql/sql_lex.h b/sql/sql_lex.h
--- a/sql/sql_lex.h	2008-04-21 01:30:30 -06:00
+++ b/sql/sql_lex.h	2008-04-21 17:03:14 -06:00
@@ -1389,7 +1389,12 @@ public:
   /** Interface with bison, value of the last token parsed. */
   LEX_YYSTYPE yylval;
 
-  /** LALR(2) resolution, look ahead token.*/
+  /**
+    LALR(2) resolution, look ahead token.
+    Value of the next token to return, if any,
+    or -1, if no token was parsed in advance.
+    Note: 0 is a legal token, and represents YYEOF.
+  */
   int lookahead_token;
 
   /** LALR(2) resolution, value of the look ahead token.*/