bzr commit into mysql-5.5-runtime branch (jon.hauglid:3142) Bug#56678

[Jon Olav Hauglid]

#At file:///export/home/x/mysql-5.5-runtime-bug56678/ based on revid:jon.hauglid@stripped

 3142 Jon Olav Hauglid	2010-09-23
      Bug #56678 Valgrind warnings from binlog.binlog_unsafe
      
      After the patch for Bug#54579, multi inserts done with INSERT DELAYED
      are binlogged as normal INSERT. During processing of the statement,
      a new query string without the DELAYED keyword is made. The problem
      was that this new string was incorrectly made when the INSERT DELAYED
      was part of a prepared statement - data was read outside the allocated
      buffer.
      
      The reason for this bug was that a pointer to the position of the
      DELAYED keyword inside the query string was stored when parsing the
      statement. This pointer was then later (at runtime) used (via pointer
      subtraction) to find the number of characters to skip when making a
      new query string without DELAYED. But when the statement was re-executed
      as part of a prepared statement, the original pointer would be invalid
      and the pointer subtraction would give a wrong/random result.
      
      This patch fixes the problem by instead storing the number of characters
      to skip at parse time. This value will not depend on the memory position
      of the query string at runtime and therefore not give wrong results
      when the statement is executed in a prepared statement.
      
      This bug was a regression introduced by the patch for Bug#54579.
      
      No test case added as this bug is already covered by the existing
      binlog.binlog_unsafe test case when running with valgrind.

    modified:
      mysql-test/suite/binlog/r/binlog_statement_insert_delayed.result
      sql/sql_insert.cc
      sql/sql_lex.h
      sql/sql_yacc.yy
=== modified file 'mysql-test/suite/binlog/r/binlog_statement_insert_delayed.result'
--- a/mysql-test/suite/binlog/r/binlog_statement_insert_delayed.result	2010-08-30 06:03:28 +0000
+++ b/mysql-test/suite/binlog/r/binlog_statement_insert_delayed.result	2010-09-23 08:24:17 +0000
@@ -28,11 +28,11 @@ show binlog events from <binlog_start>;
 Log_name	Pos	Event_type	Server_id	End_log_pos	Info
 master-bin.000001	#	Query	#	#	BEGIN
 master-bin.000001	#	Intvar	#	#	INSERT_ID=301
-master-bin.000001	#	Query	#	#	use `test`; insert /* before delayed */  /* after delayed */ into t1 values (null),(null),(null),(null)
+master-bin.000001	#	Query	#	#	use `test`; insert /* before delayed */ /* after delayed */ into t1 values (null),(null),(null),(null)
 master-bin.000001	#	Query	#	#	COMMIT
 master-bin.000001	#	Query	#	#	BEGIN
 master-bin.000001	#	Intvar	#	#	INSERT_ID=305
-master-bin.000001	#	Query	#	#	use `test`; insert  /*!  */ into t1 values (null),(null),(400),(null)
+master-bin.000001	#	Query	#	#	use `test`; insert  /*! */ into t1 values (null),(null),(400),(null)
 master-bin.000001	#	Query	#	#	COMMIT
 master-bin.000001	#	Query	#	#	use `test`; FLUSH TABLES
 select * from t1;

=== modified file 'sql/sql_insert.cc'
--- a/sql/sql_insert.cc	2010-09-15 14:15:31 +0000
+++ b/sql/sql_insert.cc	2010-09-23 08:24:17 +0000
@@ -634,14 +634,10 @@ bool open_and_lock_for_insert_delayed(TH
 static int
 create_insert_stmt_from_insert_delayed(THD *thd, String *buf)
 {
-  /* Append the part of thd->query before "DELAYED" keyword */
-  if (buf->append(thd->query(),
-                  thd->lex->keyword_delayed_begin - thd->query()))
+  /* Make a copy of thd->query() and then remove the "DELAYED" keyword */
+  if (buf->append(thd->query()) ||
+      buf->replace(thd->lex->keyword_delayed_begin_offset, 8, 0))
     return 1;
-  /* Append the part of thd->query after "DELAYED" keyword */
-  if (buf->append(thd->lex->keyword_delayed_begin + 7))
-    return 1;
-
   return 0;
 }
 

=== modified file 'sql/sql_lex.h'
--- a/sql/sql_lex.h	2010-09-01 13:12:42 +0000
+++ b/sql/sql_lex.h	2010-09-23 08:24:17 +0000
@@ -2355,12 +2355,12 @@ struct LEX: public Query_tables_list
     This pointer is required to add possibly omitted DEFINER-clause to the
     DDL-statement before dumping it to the binlog.
 
-    keyword_delayed_begin points to the begin of the DELAYED keyword in
-    INSERT DELAYED statement.
+    keyword_delayed_begin_offset is the offset to the beginning of the DELAYED
+    keyword in INSERT DELAYED statement.
   */
   union {
     const char *stmt_definition_begin;
-    const char *keyword_delayed_begin;
+    uint keyword_delayed_begin_offset;
   };
 
   const char *stmt_definition_end;

=== modified file 'sql/sql_yacc.yy'
--- a/sql/sql_yacc.yy	2010-09-09 14:29:14 +0000
+++ b/sql/sql_yacc.yy	2010-09-23 08:24:17 +0000
@@ -10447,7 +10447,8 @@ insert_lock_option:
         | LOW_PRIORITY  { $$= TL_WRITE_LOW_PRIORITY; }
         | DELAYED_SYM
         {
-          Lex->keyword_delayed_begin= YYLIP->get_tok_start();
+          Lex->keyword_delayed_begin_offset= (uint)(YYLIP->get_tok_start() -
+                                                    YYTHD->query());
           $$= TL_WRITE_DELAYED;
         }
         | HIGH_PRIORITY { $$= TL_WRITE; }
@@ -10457,7 +10458,8 @@ replace_lock_option:
           opt_low_priority { $$= $1; }
         | DELAYED_SYM
         {
-          Lex->keyword_delayed_begin= YYLIP->get_tok_start();
+          Lex->keyword_delayed_begin_offset= (uint)(YYLIP->get_tok_start() -
+                                                    YYTHD->query());
           $$= TL_WRITE_DELAYED;
         }
         ;


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