manual merge 5.0-runtime -> 5.1->runtime, with 25411 part I

18 files changed, 477 insertions, 298 deletions

diff --git a/sql/event_data_objects.cc b/sql/event_data_objects.cc
index f5847e603e8..4b788a8f7d8 100644
--- a/sql/event_data_objects.cc
+++ b/sql/event_data_objects.cc
@@ -156,10 +156,14 @@ void
 Event_parse_data::init_body(THD *thd)
 {
   DBUG_ENTER("Event_parse_data::init_body");
+
+  /* This method is called from within the parser, from sql_yacc.yy */
+  DBUG_ASSERT(thd->m_lip != NULL);
+
   DBUG_PRINT("info", ("body: '%s'  body_begin: 0x%lx end: 0x%lx", body_begin,
-                      (long) body_begin, (long) thd->lex->ptr));
+                      (long) body_begin, (long) thd->m_lip->ptr));
 
-  body.length= thd->lex->ptr - body_begin;
+  body.length= thd->m_lip->ptr - body_begin;
   const char *body_end= body_begin + body.length - 1;
 
   /* Trim nuls or close-comments ('*'+'/') or spaces at the end */
@@ -1912,15 +1916,20 @@ Event_job_data::execute(THD *thd, bool drop)
   thd->query= sp_sql.c_ptr_safe();
   thd->query_length= sp_sql.length();
 
-  lex_start(thd, thd->query, thd->query_length);
-
-  if (MYSQLparse(thd) || thd->is_fatal_error)
   {
-    sql_print_error("Event Scheduler: "
-                    "%serror during compilation of %s.%s",
-                    thd->is_fatal_error ? "fatal " : "",
-                    (const char *) dbname.str, (const char *) name.str);
-    goto end;
+    Lex_input_stream lip(thd, thd->query, thd->query_length);
+    thd->m_lip= &lip;
+    lex_start(thd);
+    int err= MYSQLparse(thd);
+
+    if (err || thd->is_fatal_error)
+    {
+      sql_print_error("Event Scheduler: "
+                      "%serror during compilation of %s.%s",
+                      thd->is_fatal_error ? "fatal " : "",
+                      (const char *) dbname.str, (const char *) name.str);
+      goto end;
+    }
   }
 
   {
diff --git a/sql/ha_ndbcluster.cc b/sql/ha_ndbcluster.cc
index 58d34d99174..d1e6ae56cb2 100644
--- a/sql/ha_ndbcluster.cc
+++ b/sql/ha_ndbcluster.cc
@@ -6564,7 +6564,7 @@ int ndb_create_table_from_engine(THD *thd, const char *db,
   LEX *old_lex= thd->lex, newlex;
   thd->lex= &newlex;
   newlex.current_select= NULL;
-  lex_start(thd, "", 0);
+  lex_start(thd);
   int res= ha_create_table_from_engine(thd, db, table_name);
   thd->lex= old_lex;
   return res;
diff --git a/sql/ha_ndbcluster_binlog.cc b/sql/ha_ndbcluster_binlog.cc
index c65c81c088c..a7c2d1f51e9 100644
--- a/sql/ha_ndbcluster_binlog.cc
+++ b/sql/ha_ndbcluster_binlog.cc
@@ -230,6 +230,7 @@ static void run_query(THD *thd, char *buf, char *end,
   ulonglong save_thd_options= thd->options;
   DBUG_ASSERT(sizeof(save_thd_options) == sizeof(thd->options));
   NET save_net= thd->net;
+  const char* found_semicolon= NULL;
 
   bzero((char*) &thd->net, sizeof(NET));
   thd->query_length= end - buf;
@@ -239,7 +240,7 @@ static void run_query(THD *thd, char *buf, char *end,
     thd->options&= ~OPTION_BIN_LOG;
     
   DBUG_PRINT("query", ("%s", thd->query));
-  mysql_parse(thd, thd->query, thd->query_length);
+  mysql_parse(thd, thd->query, thd->query_length, &found_semicolon);
 
   if (print_error && thd->query_error)
   {
diff --git a/sql/log_event.cc b/sql/log_event.cc
index 048db4ac95d..591a91f2011 100644
--- a/sql/log_event.cc
+++ b/sql/log_event.cc
@@ -5863,7 +5863,7 @@ int Rows_log_event::do_apply_event(RELAY_LOG_INFO const *rli)
       Table_map_log_event::do_apply_event() we don't call
       mysql_init_query() as that may reset the binlog format.
     */
-    lex_start(thd, NULL, 0);
+    lex_start(thd);
 
     while ((error= lock_tables(thd, rli->tables_to_lock,
                                rli->tables_to_lock_count, &need_reopen)))
@@ -6513,7 +6513,8 @@ int Table_map_log_event::do_apply_event(RELAY_LOG_INFO const *rli)
       initialized, so we should call lex_start(); to be even safer, we
       call mysql_init_query() which does a more complete set of inits.
     */
-    mysql_init_query(thd, NULL, 0);
+    lex_start(thd);
+    mysql_reset_thd_for_next_command(thd);
     /*
       Check if the slave is set to use SBR.  If so, it should switch
       to using RBR until the end of the "statement", i.e., next
diff --git a/sql/mysql_priv.h b/sql/mysql_priv.h
index 3a01ed27f61..d9386c9f4d7 100644
--- a/sql/mysql_priv.h
+++ b/sql/mysql_priv.h
@@ -838,13 +838,15 @@ bool do_rename(THD *thd, TABLE_LIST *ren_table, char *new_db,
                       bool skip_error);
 bool mysql_change_db(THD *thd, const LEX_STRING *new_db_name,
                      bool force_switch);
-void mysql_parse(THD *thd,char *inBuf,uint length);
+
+void mysql_parse(THD *thd, const char *inBuf, uint length,
+                 const char ** semicolon);
+
 bool mysql_test_parse_for_slave(THD *thd,char *inBuf,uint length);
 bool is_update_query(enum enum_sql_command command);
 bool alloc_query(THD *thd, const char *packet, uint packet_length);
 void mysql_init_select(LEX *lex);
 void mysql_reset_thd_for_next_command(THD *thd);
-void mysql_init_query(THD *thd, const char *buf, uint length);
 bool mysql_new_select(LEX *lex, bool move_down);
 void create_select_for_variable(const char *var_name);
 void mysql_init_multi_delete(LEX *lex);
diff --git a/sql/slave.cc b/sql/slave.cc
index f1b9ea8476b..f89a56e2087 100644
--- a/sql/slave.cc
+++ b/sql/slave.cc
@@ -923,6 +923,7 @@ static int create_table_from_dump(THD* thd, MYSQL *mysql, const char* db,
   handler *file;
   ulonglong save_options;
   NET *net= &mysql->net;
+  const char *found_semicolon= NULL;
   DBUG_ENTER("create_table_from_dump");
 
   packet_len= my_net_read(net); // read create table statement
@@ -974,7 +975,7 @@ static int create_table_from_dump(THD* thd, MYSQL *mysql, const char* db,
   thd->db = (char*)db;
   DBUG_ASSERT(thd->db != 0);
   thd->db_length= strlen(thd->db);
-  mysql_parse(thd, thd->query, packet_len); // run create table
+  mysql_parse(thd, thd->query, packet_len, &found_semicolon); // run create table
   thd->db = save_db;            // leave things the way the were before
   thd->db_length= save_db_length;
   thd->options = save_options;
diff --git a/sql/sp.cc b/sql/sp.cc
index 49b8b304e76..0a99be3f970 100644
--- a/sql/sp.cc
+++ b/sql/sp.cc
@@ -384,10 +384,15 @@ db_load_routine(THD *thd, int type, sp_name *name, sp_head **sphp,
   if ((ret= sp_use_new_db(thd, name->m_db, &old_db, 1, &dbchanged)))
     goto end;
 
-  lex_start(thd, defstr.c_ptr(), defstr.length());
+  {
+    Lex_input_stream lip(thd, defstr.c_ptr(), defstr.length());
+    thd->m_lip= &lip;
+    lex_start(thd);
+    ret= MYSQLparse(thd);
+  }
 
   thd->spcont= 0;
-  if (MYSQLparse(thd) || thd->is_fatal_error || newlex.sphead == NULL)
+  if (ret || thd->is_fatal_error || newlex.sphead == NULL)
   {
     sp_head *sp= newlex.sphead;
 
diff --git a/sql/sp_head.cc b/sql/sp_head.cc
index 04a7b2574a4..89fcd80abcf 100644
--- a/sql/sp_head.cc
+++ b/sql/sp_head.cc
@@ -557,6 +557,7 @@ sp_head::init_strings(THD *thd, LEX *lex)
   const char *endp;                            /* Used to trim the end */
   /* During parsing, we must use thd->mem_root */
   MEM_ROOT *root= thd->mem_root;
+  Lex_input_stream *lip=thd->m_lip;
 
   if (m_param_begin && m_param_end)
   {
@@ -565,7 +566,7 @@ sp_head::init_strings(THD *thd, LEX *lex)
   }
 
   /* If ptr has overrun end_of_query then end_of_query is the end */
-  endp= (lex->ptr > lex->end_of_query ? lex->end_of_query : lex->ptr);
+  endp= (lip->ptr > lip->end_of_query ? lip->end_of_query : lip->ptr);
   /*
     Trim "garbage" at the end. This is sometimes needed with the
     "/ * ! VERSION... * /" wrapper in dump files.
@@ -574,8 +575,8 @@ sp_head::init_strings(THD *thd, LEX *lex)
 
   m_body.length= endp - m_body_begin;
   m_body.str= strmake_root(root, m_body_begin, m_body.length);
-  m_defstr.length= endp - lex->buf;
-  m_defstr.str= strmake_root(root, lex->buf, m_defstr.length);
+  m_defstr.length= endp - lip->buf;
+  m_defstr.str= strmake_root(root, lip->buf, m_defstr.length);
   DBUG_VOID_RETURN;
 }
 
@@ -1815,25 +1816,13 @@ sp_head::reset_lex(THD *thd)
   DBUG_ENTER("sp_head::reset_lex");
   LEX *sublex;
   LEX *oldlex= thd->lex;
-  my_lex_states org_next_state= oldlex->next_state;
 
   (void)m_lex.push_front(oldlex);
   thd->lex= sublex= new st_lex;
 
-  /* Reset most stuff. The length arguments doesn't matter here. */
-  lex_start(thd, oldlex->buf, (ulong) (oldlex->end_of_query - oldlex->ptr));
+  /* Reset most stuff. */
+  lex_start(thd);
 
-  /*
-    next_state is normally the same (0), but it happens that we swap lex in
-    "mid-sentence", so we must restore it.
-   */
-  sublex->next_state= org_next_state;
-  /* We must reset ptr and end_of_query again */
-  sublex->ptr= oldlex->ptr;
-  sublex->end_of_query= oldlex->end_of_query;
-  sublex->tok_start= oldlex->tok_start;
-  sublex->tok_end= oldlex->tok_end;
-  sublex->yylineno= oldlex->yylineno;
   /* And keep the SP stuff too */
   sublex->sphead= oldlex->sphead;
   sublex->spcont= oldlex->spcont;
@@ -1866,10 +1855,6 @@ sp_head::restore_lex(THD *thd)
   if (! oldlex)
     return;			// Nothing to restore
 
-  // Update some state in the old one first
-  oldlex->ptr= sublex->ptr;
-  oldlex->tok_end= sublex->tok_end;
-  oldlex->next_state= sublex->next_state;
   oldlex->trg_table_fields.push_back(&sublex->trg_table_fields);
 
   /*
diff --git a/sql/sp_head.h b/sql/sp_head.h
index 551707fa7bd..51ca529bed0 100644
--- a/sql/sp_head.h
+++ b/sql/sp_head.h
@@ -176,7 +176,9 @@ public:
   */
   HASH m_sroutines;
   // Pointers set during parsing
-  const char *m_param_begin, *m_param_end, *m_body_begin;
+  const char *m_param_begin;
+  const char *m_param_end;
+  const char *m_body_begin;
 
   /*
     Security context for stored routine which should be run under
diff --git a/sql/sql_class.h b/sql/sql_class.h
index 48a88087fd3..fd88df4bcc8 100644
--- a/sql/sql_class.h
+++ b/sql/sql_class.h
@@ -31,6 +31,7 @@ class Load_log_event;
 class Slave_log_event;
 class sp_rcontext;
 class sp_cache;
+class Lex_input_stream;
 class Rows_log_event;
 
 enum enum_enable_or_disable { LEAVE_AS_IS, ENABLE, DISABLE };
@@ -1423,6 +1424,16 @@ public:
     */
     query_id_t first_query_id;
   } binlog_evt_union;
+
+  /**
+    Character input stream consumed by the lexical analyser,
+    used during parsing.
+    Note that since the parser is not re-entrant, we keep only one input
+    stream here. This member is valid only when executing code during parsing,
+    and may point to invalid memory after that.
+  */
+  Lex_input_stream *m_lip;
+
 #ifdef WITH_PARTITION_STORAGE_ENGINE
   partition_info *work_part_info;
 #endif
diff --git a/sql/sql_lex.cc b/sql/sql_lex.cc
index 4a162478388..24c4f42b32a 100644
--- a/sql/sql_lex.cc
+++ b/sql/sql_lex.cc
@@ -33,13 +33,13 @@ sys_var *trg_new_row_fake_var= (sys_var*) 0x01;
 
 /* Macros to look like lex */
 
-#define yyGet()         ((uchar) *(lex->ptr++))
-#define yyGetLast()     ((uchar) lex->ptr[-1])
-#define yyPeek()        ((uchar) lex->ptr[0])
-#define yyPeek2()       ((uchar) lex->ptr[1])
-#define yyUnget()	lex->ptr--
-#define yySkip()	lex->ptr++
-#define yyLength()	((uint) (lex->ptr - lex->tok_start)-1)
+#define yyGet()         ((uchar) *(lip->ptr++))
+#define yyGetLast()     ((uchar) lip->ptr[-1])
+#define yyPeek()        ((uchar) lip->ptr[0])
+#define yyPeek2()       ((uchar) lip->ptr[1])
+#define yyUnget()	lip->ptr--
+#define yySkip()	lip->ptr++
+#define yyLength()	((uint) (lip->ptr - lip->tok_start)-1)
 
 /* Longest standard keyword name */
 #define TOCK_NAME_LENGTH 24
@@ -120,6 +120,28 @@ st_parsing_options::reset()
   allows_derived= TRUE;
 }
 
+Lex_input_stream::Lex_input_stream(THD *thd,
+                                   const char* buffer,
+                                   unsigned int length)
+: m_thd(thd),
+  yylineno(1),
+  yytoklen(0),
+  yylval(NULL),
+  ptr(buffer),
+  tok_start(NULL),
+  tok_end(NULL),
+  end_of_query(buffer + length),
+  tok_start_prev(NULL),
+  buf(buffer),
+  next_state(MY_LEX_START),
+  found_semicolon(NULL),
+  ignore_space(test(thd->variables.sql_mode & MODE_IGNORE_SPACE))
+{
+}
+
+Lex_input_stream::~Lex_input_stream()
+{}
+
 
 /*
   This is called before every query that is to be parsed.
@@ -127,14 +149,12 @@ st_parsing_options::reset()
   (We already do too much here)
 */
 
-void lex_start(THD *thd, const char *buf, uint length)
+void lex_start(THD *thd)
 {
   LEX *lex= thd->lex;
   DBUG_ENTER("lex_start");
 
   lex->thd= lex->unit.thd= thd;
-  lex->buf= lex->ptr= buf;
-  lex->end_of_query= buf+length;
 
   lex->context_stack.empty();
   lex->unit.init_query();
@@ -167,14 +187,11 @@ void lex_start(THD *thd, const char *buf, uint length)
   lex->stmt_prepare_mode= FALSE;
   lex->derived_tables= 0;
   lex->lock_option= TL_READ;
-  lex->found_semicolon= 0;
   lex->safe_to_cache_query= 1;
   lex->leaf_tables_insert= 0;
   lex->parsing_options.reset();
   lex->empty_field_list_on_rset= 0;
   lex->select_lex.select_number= 1;
-  lex->next_state=MY_LEX_START;
-  lex->yylineno = 1;
   lex->in_comment=0;
   lex->length=0;
   lex->part_info= 0;
@@ -184,7 +201,6 @@ void lex_start(THD *thd, const char *buf, uint length)
   lex->select_lex.ftfunc_list= &lex->select_lex.ftfunc_list_alloc;
   lex->select_lex.group_list.empty();
   lex->select_lex.order_list.empty();
-  lex->ignore_space=test(thd->variables.sql_mode & MODE_IGNORE_SPACE);
   lex->sql_command= SQLCOM_END;
   lex->duplicates= DUP_ERROR;
   lex->ignore= 0;
@@ -236,24 +252,24 @@ void lex_end(LEX *lex)
 }
 
 
-static int find_keyword(LEX *lex, uint len, bool function)
+static int find_keyword(Lex_input_stream *lip, uint len, bool function)
 {
-  const char *tok= lex->tok_start;
+  const char *tok= lip->tok_start;
 
   SYMBOL *symbol= get_hash_symbol(tok, len, function);
   if (symbol)
   {
-    lex->yylval->symbol.symbol=symbol;
-    lex->yylval->symbol.str= (char*) tok;
-    lex->yylval->symbol.length=len;
-    
+    lip->yylval->symbol.symbol=symbol;
+    lip->yylval->symbol.str= (char*) tok;
+    lip->yylval->symbol.length=len;
+
     if ((symbol->tok == NOT_SYM) &&
-        (lex->thd->variables.sql_mode & MODE_HIGH_NOT_PRECEDENCE))
+        (lip->m_thd->variables.sql_mode & MODE_HIGH_NOT_PRECEDENCE))
       return NOT2_SYM;
     if ((symbol->tok == OR_OR_SYM) &&
-	!(lex->thd->variables.sql_mode & MODE_PIPES_AS_CONCAT))
+	!(lip->m_thd->variables.sql_mode & MODE_PIPES_AS_CONCAT))
       return OR2_SYM;
-    
+
     return symbol->tok;
   }
   return 0;
@@ -286,12 +302,12 @@ bool is_lex_native_function(const LEX_STRING *name)
 
 /* make a copy of token before ptr and set yytoklen */
 
-static LEX_STRING get_token(LEX *lex,uint length)
+static LEX_STRING get_token(Lex_input_stream *lip, uint length)
 {
   LEX_STRING tmp;
   yyUnget();			// ptr points now after last token char
-  tmp.length=lex->yytoklen=length;
-  tmp.str=(char*) lex->thd->strmake((char*) lex->tok_start,tmp.length);
+  tmp.length=lip->yytoklen=length;
+  tmp.str= lip->m_thd->strmake(lip->tok_start, tmp.length);
   return tmp;
 }
 
@@ -302,15 +318,16 @@ static LEX_STRING get_token(LEX *lex,uint length)
    future to operate multichar strings (like ucs2)
 */
 
-static LEX_STRING get_quoted_token(LEX *lex,uint length, char quote)
+static LEX_STRING get_quoted_token(Lex_input_stream *lip,
+                                   uint length, char quote)
 {
   LEX_STRING tmp;
   const char *from, *end;
   char *to;
   yyUnget();			// ptr points now after last token char
-  tmp.length=lex->yytoklen=length;
-  tmp.str=(char*) lex->thd->alloc(tmp.length+1);
-  for (from= lex->tok_start, to= tmp.str, end= to+length ;
+  tmp.length= lip->yytoklen=length;
+  tmp.str=(char*) lip->m_thd->alloc(tmp.length+1);
+  for (from= lip->tok_start, to= tmp.str, end= to+length ;
        to != end ;
        )
   {
@@ -327,31 +344,31 @@ static LEX_STRING get_quoted_token(LEX *lex,uint length, char quote)
   Fix sometimes to do only one scan of the string
 */
 
-static char *get_text(LEX *lex)
+static char *get_text(Lex_input_stream *lip)
 {
   reg1 uchar c,sep;
   uint found_escape=0;
-  CHARSET_INFO *cs= lex->thd->charset();
+  CHARSET_INFO *cs= lip->m_thd->charset();
 
   sep= yyGetLast();			// String should end with this
-  while (lex->ptr != lex->end_of_query)
+  while (lip->ptr != lip->end_of_query)
   {
     c = yyGet();
 #ifdef USE_MB
     {
       int l;
       if (use_mb(cs) &&
-          (l = my_ismbchar(cs, lex->ptr-1, lex->end_of_query))) {
-	lex->ptr += l-1;
+          (l = my_ismbchar(cs, lip->ptr-1, lip->end_of_query))) {
+	lip->ptr += l-1;
 	continue;
       }
     }
 #endif
     if (c == '\\' &&
-	!(lex->thd->variables.sql_mode & MODE_NO_BACKSLASH_ESCAPES))
+        !(lip->m_thd->variables.sql_mode & MODE_NO_BACKSLASH_ESCAPES))
     {					// Escaped character
       found_escape=1;
-      if (lex->ptr == lex->end_of_query)
+      if (lip->ptr == lip->end_of_query)
 	return 0;
       yySkip();
     }
@@ -369,15 +386,15 @@ static char *get_text(LEX *lex)
       const char *str, *end;
       char *start;
 
-      str=lex->tok_start+1;
-      end=lex->ptr-1;
-      if (!(start= (char*) lex->thd->alloc((uint) (end-str)+1)))
+      str=lip->tok_start+1;
+      end=lip->ptr-1;
+      if (!(start= (char*) lip->m_thd->alloc((uint) (end-str)+1)))
 	return (char*) "";		// Sql_alloc has set error flag
       if (!found_escape)
       {
-	lex->yytoklen=(uint) (end-str);
-	memcpy(start,str,lex->yytoklen);
-	start[lex->yytoklen]=0;
+	lip->yytoklen=(uint) (end-str);
+	memcpy(start,str,lip->yytoklen);
+	start[lip->yytoklen]=0;
       }
       else
       {
@@ -395,7 +412,7 @@ static char *get_text(LEX *lex)
 	      continue;
 	  }
 #endif
-	  if (!(lex->thd->variables.sql_mode & MODE_NO_BACKSLASH_ESCAPES) &&
+	  if (!(lip->m_thd->variables.sql_mode & MODE_NO_BACKSLASH_ESCAPES) &&
               *str == '\\' && str+1 != end)
 	  {
 	    switch(*++str) {
@@ -432,7 +449,7 @@ static char *get_text(LEX *lex)
 	    *to++ = *str;
 	}
 	*to=0;
-	lex->yytoklen=(uint) (to-start);
+	lip->yytoklen=(uint) (to-start);
       }
       return start;
     }
@@ -545,19 +562,21 @@ int MYSQLlex(void *arg, void *yythd)
   int	tokval, result_state;
   uint length;
   enum my_lex_states state;
-  LEX	*lex= ((THD *)yythd)->lex;
+  THD *thd= (THD *)yythd;
+  Lex_input_stream *lip= thd->m_lip;
+  LEX *lex= thd->lex;
   YYSTYPE *yylval=(YYSTYPE*) arg;
-  CHARSET_INFO *cs= ((THD *) yythd)->charset();
+  CHARSET_INFO *cs= thd->charset();
   uchar *state_map= cs->state_map;
   uchar *ident_map= cs->ident_map;
 
-  lex->yylval=yylval;			// The global state
+  lip->yylval=yylval;			// The global state
 
-  lex->tok_start_prev= lex->tok_start;
+  lip->tok_start_prev= lip->tok_start;
 
-  lex->tok_start=lex->tok_end=lex->ptr;
-  state=lex->next_state;
-  lex->next_state=MY_LEX_OPERATOR_OR_IDENT;
+  lip->tok_start=lip->tok_end=lip->ptr;
+  state=lip->next_state;
+  lip->next_state=MY_LEX_OPERATOR_OR_IDENT;
   LINT_INIT(c);
   for (;;)
   {
@@ -568,9 +587,9 @@ int MYSQLlex(void *arg, void *yythd)
       for (c=yyGet() ; (state_map[c] == MY_LEX_SKIP) ; c= yyGet())
       {
 	if (c == '\n')
-	  lex->yylineno++;
+	  lip->yylineno++;
       }
-      lex->tok_start=lex->ptr-1;	// Start of real token
+      lip->tok_start=lip->ptr-1;	// Start of real token
       state= (enum my_lex_states) state_map[c];
       break;
     case MY_LEX_ESCAPE:
@@ -589,13 +608,13 @@ int MYSQLlex(void *arg, void *yythd)
         state=MY_LEX_COMMENT;
         break;
       }
-      yylval->lex_str.str=(char*) (lex->ptr=lex->tok_start);// Set to first chr
+      yylval->lex_str.str=(char*) (lip->ptr=lip->tok_start);// Set to first chr
       yylval->lex_str.length=1;
       c=yyGet();
       if (c != ')')
-	lex->next_state= MY_LEX_START;	// Allow signed numbers
+	lip->next_state= MY_LEX_START;	// Allow signed numbers
       if (c == ',')
-	lex->tok_start=lex->ptr;	// Let tok_start point at next item
+	lip->tok_start=lip->ptr;	// Let tok_start point at next item
       /*
         Check for a placeholder: it should not precede a possible identifier
         because of binlogging: when a placeholder is replaced with
@@ -613,14 +632,14 @@ int MYSQLlex(void *arg, void *yythd)
 	break;
       }
       /* Found N'string' */
-      lex->tok_start++;                 // Skip N
+      lip->tok_start++;                 // Skip N
       yySkip();                         // Skip '
-      if (!(yylval->lex_str.str = get_text(lex)))
+      if (!(yylval->lex_str.str = get_text(lip)))
       {
 	state= MY_LEX_CHAR;             // Read char by char
 	break;
       }
-      yylval->lex_str.length= lex->yytoklen;
+      yylval->lex_str.length= lip->yytoklen;
       return(NCHAR_STRING);
 
     case MY_LEX_IDENT_OR_HEX:
@@ -643,21 +662,21 @@ int MYSQLlex(void *arg, void *yythd)
 	result_state= IDENT_QUOTED;
         if (my_mbcharlen(cs, yyGetLast()) > 1)
         {
-          int l = my_ismbchar(cs, lex->ptr-1, lex->end_of_query);
+          int l = my_ismbchar(cs, lip->ptr-1, lip->end_of_query);
           if (l == 0) {
             state = MY_LEX_CHAR;
             continue;
           }
-          lex->ptr += l - 1;
+          lip->ptr += l - 1;
         }
         while (ident_map[c=yyGet()])
         {
           if (my_mbcharlen(cs, c) > 1)
           {
             int l;
-            if ((l = my_ismbchar(cs, lex->ptr-1, lex->end_of_query)) == 0)
+            if ((l = my_ismbchar(cs, lip->ptr-1, lip->end_of_query)) == 0)
               break;
-            lex->ptr += l-1;
+            lip->ptr += l-1;
           }
         }
       }
@@ -668,9 +687,9 @@ int MYSQLlex(void *arg, void *yythd)
         /* If there were non-ASCII characters, mark that we must convert */
         result_state= result_state & 0x80 ? IDENT_QUOTED : IDENT;
       }
-      length= (uint) (lex->ptr - lex->tok_start)-1;
-      start= lex->ptr;
-      if (lex->ignore_space)
+      length= (uint) (lip->ptr - lip->tok_start)-1;
+      start= lip->ptr;
+      if (lip->ignore_space)
       {
         /*
           If we find a space then this can't be an identifier. We notice this
@@ -678,19 +697,19 @@ int MYSQLlex(void *arg, void *yythd)
         */
         for (; state_map[c] == MY_LEX_SKIP ; c= yyGet());
       }
-      if (start == lex->ptr && c == '.' && ident_map[yyPeek()])
-	lex->next_state=MY_LEX_IDENT_SEP;
+      if (start == lip->ptr && c == '.' && ident_map[yyPeek()])
+	lip->next_state=MY_LEX_IDENT_SEP;
       else
       {					// '(' must follow directly if function
 	yyUnget();
-	if ((tokval = find_keyword(lex,length,c == '(')))
+	if ((tokval = find_keyword(lip, length,c == '(')))
 	{
-	  lex->next_state= MY_LEX_START;	// Allow signed numbers
+	  lip->next_state= MY_LEX_START;	// Allow signed numbers
 	  return(tokval);		// Was keyword
 	}
 	yySkip();			// next state does a unget
       }
-      yylval->lex_str=get_token(lex,length);
+      yylval->lex_str=get_token(lip, length);
 
       /* 
          Note: "SELECT _bla AS 'alias'"
@@ -707,12 +726,12 @@ int MYSQLlex(void *arg, void *yythd)
       return(result_state);			// IDENT or IDENT_QUOTED
 
     case MY_LEX_IDENT_SEP:		// Found ident and now '.'
-      yylval->lex_str.str=(char*) lex->ptr;
+      yylval->lex_str.str=(char*) lip->ptr;
       yylval->lex_str.length=1;
       c=yyGet();			// should be '.'
-      lex->next_state= MY_LEX_IDENT_START;// Next is an ident (not a keyword)
+      lip->next_state= MY_LEX_IDENT_START;// Next is an ident (not a keyword)
       if (!ident_map[yyPeek()])		// Probably ` or "
-	lex->next_state= MY_LEX_START;
+	lip->next_state= MY_LEX_START;
       return((int) c);
 
     case MY_LEX_NUMBER_IDENT:		// number or ident which num-start
@@ -732,36 +751,36 @@ int MYSQLlex(void *arg, void *yythd)
 	  {
 	    yySkip();
 	    while (my_isdigit(cs,yyGet())) ;
-	    yylval->lex_str=get_token(lex,yyLength());
+	    yylval->lex_str=get_token(lip, yyLength());
 	    return(FLOAT_NUM);
 	  }
 	}
 	yyUnget(); /* purecov: inspected */
       }
-      else if (c == 'x' && (lex->ptr - lex->tok_start) == 2 &&
-	  lex->tok_start[0] == '0' )
+      else if (c == 'x' && (lip->ptr - lip->tok_start) == 2 &&
+	  lip->tok_start[0] == '0' )
       {						// Varbinary
 	while (my_isxdigit(cs,(c = yyGet()))) ;
-	if ((lex->ptr - lex->tok_start) >= 4 && !ident_map[c])
+	if ((lip->ptr - lip->tok_start) >= 4 && !ident_map[c])
 	{
-	  yylval->lex_str=get_token(lex,yyLength());
+	  yylval->lex_str=get_token(lip, yyLength());
 	  yylval->lex_str.str+=2;		// Skip 0x
 	  yylval->lex_str.length-=2;
-	  lex->yytoklen-=2;
+	  lip->yytoklen-=2;
 	  return (HEX_NUM);
 	}
 	yyUnget();
       }
-      else if (c == 'b' && (lex->ptr - lex->tok_start) == 2 &&
-               lex->tok_start[0] == '0' )
+      else if (c == 'b' && (lip->ptr - lip->tok_start) == 2 &&
+               lip->tok_start[0] == '0' )
       {						// b'bin-number'
 	while (my_isxdigit(cs,(c = yyGet()))) ;
-	if ((lex->ptr - lex->tok_start) >= 4 && !ident_map[c])
+	if ((lip->ptr - lip->tok_start) >= 4 && !ident_map[c])
 	{
-	  yylval->lex_str= get_token(lex, yyLength());
+	  yylval->lex_str= get_token(lip, yyLength());
 	  yylval->lex_str.str+= 2;		// Skip 0x
 	  yylval->lex_str.length-= 2;
-	  lex->yytoklen-= 2;
+	  lip->yytoklen-= 2;
 	  return (BIN_NUM);
 	}
 	yyUnget();
@@ -778,9 +797,9 @@ int MYSQLlex(void *arg, void *yythd)
           if (my_mbcharlen(cs, c) > 1)
           {
             int l;
-            if ((l = my_ismbchar(cs, lex->ptr-1, lex->end_of_query)) == 0)
+            if ((l = my_ismbchar(cs, lip->ptr-1, lip->end_of_query)) == 0)
               break;
-            lex->ptr += l-1;
+            lip->ptr += l-1;
           }
         }
       }
@@ -792,16 +811,16 @@ int MYSQLlex(void *arg, void *yythd)
         result_state= result_state & 0x80 ? IDENT_QUOTED : IDENT;
       }
       if (c == '.' && ident_map[yyPeek()])
-	lex->next_state=MY_LEX_IDENT_SEP;// Next is '.'
+	lip->next_state=MY_LEX_IDENT_SEP;// Next is '.'
 
-      yylval->lex_str= get_token(lex,yyLength());
+      yylval->lex_str= get_token(lip, yyLength());
       return(result_state);
 
     case MY_LEX_USER_VARIABLE_DELIMITER:	// Found quote char
     {
       uint double_quotes= 0;
       char quote_char= c;                       // Used char
-      lex->tok_start=lex->ptr;			// Skip first `
+      lip->tok_start=lip->ptr;			// Skip first `
       while ((c=yyGet()))
       {
 	int var_length;
@@ -819,23 +838,23 @@ int MYSQLlex(void *arg, void *yythd)
 #ifdef USE_MB
 	else if (var_length < 1)
 	  break;				// Error
-	lex->ptr+= var_length-1;
+	lip->ptr+= var_length-1;
 #endif
       }
       if (double_quotes)
-	yylval->lex_str=get_quoted_token(lex,yyLength() - double_quotes,
+	yylval->lex_str=get_quoted_token(lip, yyLength() - double_quotes,
 					 quote_char);
       else
-	yylval->lex_str=get_token(lex,yyLength());
+	yylval->lex_str=get_token(lip, yyLength());
       if (c == quote_char)
 	yySkip();			// Skip end `
-      lex->next_state= MY_LEX_START;
+      lip->next_state= MY_LEX_START;
       return(IDENT_QUOTED);
     }
     case MY_LEX_INT_OR_REAL:		// Compleat int or incompleat real
       if (c != '.')
       {					// Found complete integer number.
-	yylval->lex_str=get_token(lex,yyLength());
+	yylval->lex_str=get_token(lip, yyLength());
 	return int_token(yylval->lex_str.str,yylval->lex_str.length);
       }
       // fall through
@@ -853,47 +872,47 @@ int MYSQLlex(void *arg, void *yythd)
 	  break;
 	}
 	while (my_isdigit(cs,yyGet())) ;
-	yylval->lex_str=get_token(lex,yyLength());
+	yylval->lex_str=get_token(lip, yyLength());
 	return(FLOAT_NUM);
       }
-      yylval->lex_str=get_token(lex,yyLength());
+      yylval->lex_str=get_token(lip, yyLength());
       return(DECIMAL_NUM);
 
     case MY_LEX_HEX_NUMBER:		// Found x'hexstring'
       yyGet();				// Skip '
       while (my_isxdigit(cs,(c = yyGet()))) ;
-      length=(lex->ptr - lex->tok_start);	// Length of hexnum+3
+      length=(lip->ptr - lip->tok_start);	// Length of hexnum+3
       if (!(length & 1) || c != '\'')
       {
 	return(ABORT_SYM);		// Illegal hex constant
       }
       yyGet();				// get_token makes an unget
-      yylval->lex_str=get_token(lex,length);
+      yylval->lex_str=get_token(lip, length);
       yylval->lex_str.str+=2;		// Skip x'
       yylval->lex_str.length-=3;	// Don't count x' and last '
-      lex->yytoklen-=3;
+      lip->yytoklen-=3;
       return (HEX_NUM);
 
     case MY_LEX_BIN_NUMBER:           // Found b'bin-string'
       yyGet();                                // Skip '
       while ((c= yyGet()) == '0' || c == '1');
-      length= (lex->ptr - lex->tok_start);    // Length of bin-num + 3
+      length= (lip->ptr - lip->tok_start);    // Length of bin-num + 3
       if (c != '\'')
       return(ABORT_SYM);              // Illegal hex constant
       yyGet();                        // get_token makes an unget
-      yylval->lex_str= get_token(lex, length);
+      yylval->lex_str= get_token(lip, length);
       yylval->lex_str.str+= 2;        // Skip b'
       yylval->lex_str.length-= 3;     // Don't count b' and last '
-      lex->yytoklen-= 3;
+      lip->yytoklen-= 3;
       return (BIN_NUM); 
 
     case MY_LEX_CMP_OP:			// Incomplete comparison operator
       if (state_map[yyPeek()] == MY_LEX_CMP_OP ||
 	  state_map[yyPeek()] == MY_LEX_LONG_CMP_OP)
 	yySkip();
-      if ((tokval = find_keyword(lex,(uint) (lex->ptr - lex->tok_start),0)))
+      if ((tokval = find_keyword(lip, (uint) (lip->ptr - lip->tok_start),0)))
       {
-	lex->next_state= MY_LEX_START;	// Allow signed numbers
+	lip->next_state= MY_LEX_START;	// Allow signed numbers
 	return(tokval);
       }
       state = MY_LEX_CHAR;		// Something fishy found
@@ -907,9 +926,9 @@ int MYSQLlex(void *arg, void *yythd)
 	if (state_map[yyPeek()] == MY_LEX_CMP_OP)
 	  yySkip();
       }
-      if ((tokval = find_keyword(lex,(uint) (lex->ptr - lex->tok_start),0)))
+      if ((tokval = find_keyword(lip, (uint) (lip->ptr - lip->tok_start),0)))
       {
-	lex->next_state= MY_LEX_START;	// Found long op
+	lip->next_state= MY_LEX_START;	// Found long op
 	return(tokval);
       }
       state = MY_LEX_CHAR;		// Something fishy found
@@ -922,24 +941,24 @@ int MYSQLlex(void *arg, void *yythd)
 	break;
       }
       yySkip();
-      tokval = find_keyword(lex,2,0);	// Is a bool operator
-      lex->next_state= MY_LEX_START;	// Allow signed numbers
+      tokval = find_keyword(lip,2,0);	// Is a bool operator
+      lip->next_state= MY_LEX_START;	// Allow signed numbers
       return(tokval);
 
     case MY_LEX_STRING_OR_DELIMITER:
-      if (((THD *) yythd)->variables.sql_mode & MODE_ANSI_QUOTES)
+      if (thd->variables.sql_mode & MODE_ANSI_QUOTES)
       {
 	state= MY_LEX_USER_VARIABLE_DELIMITER;
 	break;
       }
       /* " used for strings */
     case MY_LEX_STRING:			// Incomplete text string
-      if (!(yylval->lex_str.str = get_text(lex)))
+      if (!(yylval->lex_str.str = get_text(lip)))
       {
 	state= MY_LEX_CHAR;		// Read char by char
 	break;
       }
-      yylval->lex_str.length=lex->yytoklen;
+      yylval->lex_str.length=lip->yytoklen;
       return(TEXT_STRING);
 
     case MY_LEX_COMMENT:			//  Comment
@@ -963,7 +982,7 @@ int MYSQLlex(void *arg, void *yythd)
 	state=MY_LEX_START;
 	if (my_isdigit(cs,yyPeek()))
 	{				// Version number
-	  version=strtol((char*) lex->ptr,(char**) &lex->ptr,10);
+	  version=strtol((char*) lip->ptr,(char**) &lip->ptr,10);
 	}
 	if (version <= MYSQL_VERSION_ID)
 	{
@@ -971,13 +990,13 @@ int MYSQLlex(void *arg, void *yythd)
 	  break;
 	}
       }
-      while (lex->ptr != lex->end_of_query &&
+      while (lip->ptr != lip->end_of_query &&
 	     ((c=yyGet()) != '*' || yyPeek() != '/'))
       {
 	if (c == '\n')
-	  lex->yylineno++;
+	  lip->yylineno++;
       }
-      if (lex->ptr != lex->end_of_query)
+      if (lip->ptr != lip->end_of_query)
 	yySkip();			// remove last '/'
       state = MY_LEX_START;		// Try again
       break;
@@ -1002,14 +1021,13 @@ int MYSQLlex(void *arg, void *yythd)
     case MY_LEX_SEMICOLON:			// optional line terminator
       if (yyPeek())
       {
-        THD* thd= (THD*)yythd;
         if ((thd->client_capabilities & CLIENT_MULTI_STATEMENTS) && 
             !lex->stmt_prepare_mode)
         {
 	  lex->safe_to_cache_query= 0;
-          lex->found_semicolon=(char*) lex->ptr;
+          lip->found_semicolon= lip->ptr;
           thd->server_status|= SERVER_MORE_RESULTS_EXISTS;
-          lex->next_state=     MY_LEX_END;
+          lip->next_state= MY_LEX_END;
           return (END_OF_INPUT);
         }
         state= MY_LEX_CHAR;		// Return ';'
@@ -1017,15 +1035,15 @@ int MYSQLlex(void *arg, void *yythd)
       }
       /* fall true */
     case MY_LEX_EOL:
-      if (lex->ptr >= lex->end_of_query)
+      if (lip->ptr >= lip->end_of_query)
       {
-	lex->next_state=MY_LEX_END;	// Mark for next loop
+	lip->next_state=MY_LEX_END;	// Mark for next loop
 	return(END_OF_INPUT);
       }
       state=MY_LEX_CHAR;
       break;
     case MY_LEX_END:
-      lex->next_state=MY_LEX_END;
+      lip->next_state=MY_LEX_END;
       return(0);			// We found end of input last time
       
       /* Actually real shouldn't start with . but allow them anyhow */
@@ -1045,26 +1063,26 @@ int MYSQLlex(void *arg, void *yythd)
       case MY_LEX_STRING_OR_DELIMITER:
 	break;
       case MY_LEX_USER_END:
-	lex->next_state=MY_LEX_SYSTEM_VAR;
+	lip->next_state=MY_LEX_SYSTEM_VAR;
 	break;
       default:
-	lex->next_state=MY_LEX_HOSTNAME;
+	lip->next_state=MY_LEX_HOSTNAME;
 	break;
       }
-      yylval->lex_str.str=(char*) lex->ptr;
+      yylval->lex_str.str=(char*) lip->ptr;
       yylval->lex_str.length=1;
       return((int) '@');
     case MY_LEX_HOSTNAME:		// end '@' of user@hostname
       for (c=yyGet() ; 
 	   my_isalnum(cs,c) || c == '.' || c == '_' ||  c == '$';
 	   c= yyGet()) ;
-      yylval->lex_str=get_token(lex,yyLength());
+      yylval->lex_str=get_token(lip, yyLength());
       return(LEX_HOSTNAME);
     case MY_LEX_SYSTEM_VAR:
-      yylval->lex_str.str=(char*) lex->ptr;
+      yylval->lex_str.str=(char*) lip->ptr;
       yylval->lex_str.length=1;
       yySkip();					// Skip '@'
-      lex->next_state= (state_map[yyPeek()] ==
+      lip->next_state= (state_map[yyPeek()] ==
 			MY_LEX_USER_VARIABLE_DELIMITER ?
 			MY_LEX_OPERATOR_OR_IDENT :
 			MY_LEX_IDENT_OR_KEYWORD);
@@ -1081,16 +1099,16 @@ int MYSQLlex(void *arg, void *yythd)
       result_state= result_state & 0x80 ? IDENT_QUOTED : IDENT;
       
       if (c == '.')
-	lex->next_state=MY_LEX_IDENT_SEP;
-      length= (uint) (lex->ptr - lex->tok_start)-1;
+	lip->next_state=MY_LEX_IDENT_SEP;
+      length= (uint) (lip->ptr - lip->tok_start)-1;
       if (length == 0) 
         return(ABORT_SYM);              // Names must be nonempty.
-      if ((tokval= find_keyword(lex,length,0)))
+      if ((tokval= find_keyword(lip, length,0)))
       {
 	yyUnget();				// Put back 'c'
 	return(tokval);				// Was keyword
       }
-      yylval->lex_str=get_token(lex,length);
+      yylval->lex_str=get_token(lip, length);
       return(result_state);
     }
   }
diff --git a/sql/sql_lex.h b/sql/sql_lex.h
index 1175776ffd3..278a59fe1ac 100644
--- a/sql/sql_lex.h
+++ b/sql/sql_lex.h
@@ -543,7 +543,7 @@ public:
   void set_thd(THD *thd_arg) { thd= thd_arg; }
   inline bool is_union (); 
 
-  friend void lex_start(THD *thd, const char *buf, uint length);
+  friend void lex_start(THD *thd);
   friend int subselect_union_engine::exec();
 
   List<Item> *get_unit_column_types();
@@ -744,7 +744,7 @@ public:
   void cut_subtree() { slave= 0; }
   bool test_limit();
 
-  friend void lex_start(THD *thd, const char *buf, uint length);
+  friend void lex_start(THD *thd);
   st_select_lex() : n_sum_items(0), n_child_sum_items(0) {}
   void make_empty_select()
   {
@@ -992,23 +992,67 @@ struct st_parsing_options
 };
 
 
+/**
+  This class represents the character input stream consumed during
+  lexical analysis.
+*/
+class Lex_input_stream
+{
+public:
+  Lex_input_stream(THD *thd, const char* buff, unsigned int length);
+  ~Lex_input_stream();
+
+  /** Current thread. */
+  THD *m_thd;
+
+  /** Current line number. */
+  uint yylineno;
+
+  /** Length of the last token parsed. */
+  uint yytoklen;
+
+  /** Interface with bison, value of the last token parsed. */
+  LEX_YYSTYPE yylval;
+
+  /** Pointer to the current position in the input stream. */
+  const char* ptr;
+
+  /** Starting position of the last token parsed. */
+  const char* tok_start;
+
+  /** Ending position of the last token parsed. */
+  const char* tok_end;
+
+  /** End of the query text in the input stream. */
+  const char* end_of_query;
+
+  /** Starting position of the previous token parsed. */
+  const char* tok_start_prev;
+
+  /** Begining of the query text in the input stream. */
+  const char* buf;
+
+  /** Current state of the lexical analyser. */
+  enum my_lex_states next_state;
+
+  /** Position of ';' in the stream, to delimit multiple queries. */
+  const char* found_semicolon;
+
+  /** SQL_MODE = IGNORE_SPACE. */
+  bool ignore_space;
+};
+
+
 /* The state of the lex parsing. This is saved in the THD struct */
 
 typedef struct st_lex : public Query_tables_list
 {
-  uint	 yylineno,yytoklen;			/* Simulate lex */
-  LEX_YYSTYPE yylval;
   SELECT_LEX_UNIT unit;                         /* most upper unit */
   SELECT_LEX select_lex;                        /* first SELECT_LEX */
   /* current SELECT_LEX in parsing */
   SELECT_LEX *current_select;
   /* list of all SELECT_LEX */
   SELECT_LEX *all_selects_list;
-  const char *buf;		/* The beginning of string, used by SPs */
-  const char *ptr,*tok_start,*tok_end,*end_of_query;
-  
-  /* The value of tok_start as they were one call of MYSQLlex before */
-  const char *tok_start_prev;
 
   char *length,*dec,*change;
   LEX_STRING name;
@@ -1017,7 +1061,6 @@ typedef struct st_lex : public Query_tables_list
   char *backup_dir;				/* For RESTORE/BACKUP */
   char* to_log;                                 /* For PURGE MASTER LOGS TO */
   char* x509_subject,*x509_issuer,*ssl_cipher;
-  char* found_semicolon;                        /* For multi queries - next query */
   String *wild;
   sql_exchange *exchange;
   select_result *result;
@@ -1101,7 +1144,6 @@ typedef struct st_lex : public Query_tables_list
 
   thr_lock_type lock_option;
   enum SSL_type ssl_type;			/* defined in violite.h */
-  enum my_lex_states next_state;
   enum enum_duplicates duplicates;
   enum enum_tx_isolation tx_isolation;
   enum enum_ha_read_modes ha_read_mode;
@@ -1133,7 +1175,7 @@ typedef struct st_lex : public Query_tables_list
   uint8 create_view_algorithm;
   uint8 create_view_check;
   bool drop_if_exists, drop_temporary, local_file, one_shot_set;
-  bool in_comment, ignore_space, verbose, no_write_to_binlog;
+  bool in_comment, verbose, no_write_to_binlog;
   bool tx_chain, tx_release;
   /*
     Special JOIN::prepare mode: changing of query is prohibited.
@@ -1210,7 +1252,8 @@ typedef struct st_lex : public Query_tables_list
     Pointers to part of LOAD DATA statement that should be rewritten
     during replication ("LOCAL 'filename' REPLACE INTO" part).
   */
-  const char *fname_start, *fname_end;
+  const char *fname_start;
+  const char *fname_end;
 
   /*
     Reference to a struct that contains information in various commands
@@ -1327,7 +1370,7 @@ struct st_lex_local: public st_lex
 
 extern void lex_init(void);
 extern void lex_free(void);
-extern void lex_start(THD *thd, const char *buf, uint length);
+extern void lex_start(THD *thd);
 extern void lex_end(LEX *lex);
 extern int MYSQLlex(void *arg, void *yythd);
 extern const char *skip_rear_comments(const char *ubegin, const char *uend);
diff --git a/sql/sql_parse.cc b/sql/sql_parse.cc
index df2ac4d72fa..d2f9d31a495 100644
--- a/sql/sql_parse.cc
+++ b/sql/sql_parse.cc
@@ -300,6 +300,7 @@ pthread_handler_t handle_bootstrap(void *arg)
   THD *thd=(THD*) arg;
   FILE *file=bootstrap_file;
   char *buff;
+  const char* found_semicolon= NULL;
 
   /* The following must be called before DBUG_ENTER */
   thd->thread_stack= (char*) &thd;
@@ -375,7 +376,7 @@ pthread_handler_t handle_bootstrap(void *arg)
     */
     thd->query_id=next_query_id();
     thd->set_time();
-    mysql_parse(thd,thd->query,length);
+    mysql_parse(thd, thd->query, length, & found_semicolon);
     close_thread_tables(thd);			// Free tables
 
     if (thd->is_fatal_error)
@@ -889,17 +890,19 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
     char *packet_end= thd->query + thd->query_length;
     /* 'b' stands for 'buffer' parameter', special for 'my_snprintf' */
     const char *format= "%.*b";
+    const char* found_semicolon= NULL;
+
     general_log_print(thd, command, format, thd->query_length, thd->query);
     DBUG_PRINT("query",("%-.4096s",thd->query));
 
     if (!(specialflag & SPECIAL_NO_PRIOR))
       my_pthread_setprio(pthread_self(),QUERY_PRIOR);
 
-    mysql_parse(thd,thd->query, thd->query_length);
+    mysql_parse(thd, thd->query, thd->query_length, & found_semicolon);
 
-    while (!thd->killed && thd->lex->found_semicolon && !thd->net.report_error)
+    while (!thd->killed && found_semicolon && !thd->net.report_error)
     {
-      char *next_packet= thd->lex->found_semicolon;
+      char *next_packet= (char*) found_semicolon;
       net->no_send_error= 0;
       /*
         Multiple queries exits, execute them individually
@@ -924,7 +927,7 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
       thd->set_time(); /* Reset the query start time. */
       /* TODO: set thd->lex->sql_command to SQLCOM_END here */
       VOID(pthread_mutex_unlock(&LOCK_thread_count));
-      mysql_parse(thd, next_packet, length);
+      mysql_parse(thd, next_packet, length, & found_semicolon);
     }
 
     if (!(specialflag & SPECIAL_NO_PRIOR))
@@ -946,7 +949,7 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
     uint dummy;
 
     /* used as fields initializator */
-    lex_start(thd, 0, 0);
+    lex_start(thd);
 
     statistic_increment(thd->status_var.com_stat[SQLCOM_SHOW_FIELDS],
 			&LOCK_status);
@@ -985,7 +988,10 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
       break;
     /* init structures for VIEW processing */
     table_list.select_lex= &(thd->lex->select_lex);
-    mysql_init_query(thd, "", 0);
+
+    lex_start(thd);
+    mysql_reset_thd_for_next_command(thd);
+
     thd->lex->
       select_lex.table_list.link_in_list((byte*) &table_list,
                                          (byte**) &table_list.next_local);
@@ -5038,20 +5044,6 @@ bool my_yyoverflow(short **yyss, YYSTYPE **yyvs, ulong *yystacksize)
 }
 
 
-/****************************************************************************
-  Initialize global thd variables needed for query
-****************************************************************************/
-
-void
-mysql_init_query(THD *thd, const char *buf, uint length)
-{
-  DBUG_ENTER("mysql_init_query");
-  lex_start(thd, buf, length);
-  mysql_reset_thd_for_next_command(thd);
-  DBUG_VOID_RETURN;
-}
-
-
 /*
  Reset THD part responsible for command processing state.
 
@@ -5263,22 +5255,55 @@ void mysql_init_multi_delete(LEX *lex)
   mysql_test_parse_for_slave() in this same file.
 */
 
-void mysql_parse(THD *thd, char *inBuf, uint length)
+/**
+  Parse a query.
+  @param thd Current thread
+  @param inBuf Begining of the query text
+  @param length Length of the query text
+  @param [out] semicolon For multi queries, position of the character of
+  the next query in the query text.
+*/
+
+void mysql_parse(THD *thd, const char *inBuf, uint length,
+                 const char ** found_semicolon)
 {
   DBUG_ENTER("mysql_parse");
 
   DBUG_EXECUTE_IF("parser_debug", turn_parser_debug_on(););
 
-  mysql_init_query(thd, inBuf, length);
+  /*
+    Warning.
+    The purpose of query_cache_send_result_to_client() is to lookup the
+    query in the query cache first, to avoid parsing and executing it.
+    So, the natural implementation would be to:
+    - first, call query_cache_send_result_to_client,
+    - second, if caching failed, initialise the lexical and syntactic parser.
+    The problem is that the query cache depends on a clean initialization
+    of (among others) lex->safe_to_cache_query and thd->server_status,
+    which are reset respectively in
+    - lex_start()
+    - mysql_reset_thd_for_next_command()
+    So, initializing the lexical analyser *before* using the query cache
+    is required for the cache to work properly.
+    FIXME: cleanup the dependencies in the code to simplify this.
+  */
+  lex_start(thd);
+  mysql_reset_thd_for_next_command(thd);
 
-  if (query_cache_send_result_to_client(thd, inBuf, length) <= 0)
+  if (query_cache_send_result_to_client(thd, (char*) inBuf, length) <= 0)
   {
     LEX *lex= thd->lex;
-    
+
     sp_cache_flush_obsolete(&thd->sp_proc_cache);
     sp_cache_flush_obsolete(&thd->sp_func_cache);
-    
-    if (!MYSQLparse((void *)thd) && ! thd->is_fatal_error)
+
+    Lex_input_stream lip(thd, inBuf, length);
+    thd->m_lip= &lip;
+
+    int err= MYSQLparse(thd);
+    *found_semicolon= lip.found_semicolon;
+
+    if (!err && ! thd->is_fatal_error)
     {
 #ifndef NO_EMBEDDED_ACCESS_CHECKS
       if (mqh_used && thd->user_connect &&
@@ -5301,8 +5326,8 @@ void mysql_parse(THD *thd, char *inBuf, uint length)
             PROCESSLIST.
             Note that we don't need LOCK_thread_count to modify query_length.
           */
-          if (lex->found_semicolon &&
-              (thd->query_length= (ulong)(lex->found_semicolon - thd->query)))
+          if (lip.found_semicolon &&
+              (thd->query_length= (ulong)(lip.found_semicolon - thd->query)))
             thd->query_length--;
           /* Actually execute the query */
 	  mysql_execute_command(thd);
@@ -5329,6 +5354,12 @@ void mysql_parse(THD *thd, char *inBuf, uint length)
     thd->cleanup_after_query();
     DBUG_ASSERT(thd->change_list.is_empty());
   }
+  else
+  {
+    /* There are no multi queries in the cache. */
+    *found_semicolon= NULL;
+  }
+
   DBUG_VOID_RETURN;
 }
 
@@ -5349,8 +5380,13 @@ bool mysql_test_parse_for_slave(THD *thd, char *inBuf, uint length)
   bool error= 0;
   DBUG_ENTER("mysql_test_parse_for_slave");
 
-  mysql_init_query(thd, inBuf, length);
-  if (!MYSQLparse((void*) thd) && ! thd->is_fatal_error &&
+  Lex_input_stream lip(thd, inBuf, length);
+  thd->m_lip= &lip;
+  lex_start(thd);
+  mysql_reset_thd_for_next_command(thd);
+  int err= MYSQLparse((void*) thd);
+
+  if (!err && ! thd->is_fatal_error &&
       all_tables_not_ok(thd,(TABLE_LIST*) lex->select_lex.table_list.first))
     error= 1;                  /* Ignore question */
   thd->end_statement();
@@ -6401,8 +6437,9 @@ bool check_simple_select()
   if (lex->current_select != &lex->select_lex)
   {
     char command[80];
-    strmake(command, lex->yylval->symbol.str,
-	    min(lex->yylval->symbol.length, sizeof(command)-1));
+    Lex_input_stream *lip= thd->m_lip;
+    strmake(command, lip->yylval->symbol.str,
+	    min(lip->yylval->symbol.length, sizeof(command)-1));
     my_error(ER_CANT_USE_OPTION_HERE, MYF(0), command);
     return 1;
   }
diff --git a/sql/sql_partition.cc b/sql/sql_partition.cc
index d445c8bfbe0..47260b945fc 100644
--- a/sql/sql_partition.cc
+++ b/sql/sql_partition.cc
@@ -3718,7 +3718,11 @@ bool mysql_unpack_partition(THD *thd,
 
   thd->lex= &lex;
   thd->variables.character_set_client= system_charset_info;
-  lex_start(thd, part_buf, part_info_len);
+
+  Lex_input_stream lip(thd, part_buf, part_info_len);
+  thd->m_lip= &lip;
+
+  lex_start(thd);
   /*
     We need to use the current SELECT_LEX since I need to keep the
     Name_resolution_context object which is referenced from the
diff --git a/sql/sql_prepare.cc b/sql/sql_prepare.cc
index 31a6c7af04a..ca1b29ea57d 100644
--- a/sql/sql_prepare.cc
+++ b/sql/sql_prepare.cc
@@ -2850,10 +2850,14 @@ bool Prepared_statement::prepare(const char *packet, uint packet_len)
 
   old_stmt_arena= thd->stmt_arena;
   thd->stmt_arena= this;
-  lex_start(thd, thd->query, thd->query_length);
+
+  Lex_input_stream lip(thd, thd->query, thd->query_length);
+  thd->m_lip= &lip;
+  lex_start(thd);
   lex->stmt_prepare_mode= TRUE;
+  int err= MYSQLparse((void *)thd);
 
-  error= MYSQLparse((void *)thd) || thd->is_fatal_error ||
+  error= err || thd->is_fatal_error ||
       thd->net.report_error || init_param_array(this);
 
   /*
diff --git a/sql/sql_trigger.cc b/sql/sql_trigger.cc
index 7b4deba527a..89ac444efa9 100644
--- a/sql/sql_trigger.cc
+++ b/sql/sql_trigger.cc
@@ -976,10 +976,14 @@ bool Table_triggers_list::check_n_load(THD *thd, const char *db,
         LEX_STRING *trg_definer= it_definer++;
 
         thd->variables.sql_mode= (ulong)*trg_sql_mode;
-        lex_start(thd, trg_create_str->str, trg_create_str->length);
 
-	thd->spcont= 0;
-        if (MYSQLparse((void *)thd) || thd->is_fatal_error)
+        Lex_input_stream lip(thd, trg_create_str->str, trg_create_str->length);
+        thd->m_lip= &lip;
+        lex_start(thd);
+        thd->spcont= 0;
+        int err= MYSQLparse((void *)thd);
+
+        if (err || thd->is_fatal_error)
         {
           /* Currently sphead is always deleted in case of a parse error */
           DBUG_ASSERT(lex.sphead == 0);
diff --git a/sql/sql_view.cc b/sql/sql_view.cc
index 453cbbc091e..5eaac8acc77 100644
--- a/sql/sql_view.cc
+++ b/sql/sql_view.cc
@@ -985,10 +985,14 @@ bool mysql_make_view(THD *thd, File_parser *parser, TABLE_LIST *table,
     now Lex placed in statement memory
   */
   table->view= lex= thd->lex= (LEX*) new(thd->mem_root) st_lex_local;
-  lex_start(thd, table->query.str, table->query.length);
-  view_select= &lex->select_lex;
-  view_select->select_number= ++thd->select_number;
+
   {
+    Lex_input_stream lip(thd, table->query.str, table->query.length);
+    thd->m_lip= &lip;
+    lex_start(thd);
+    view_select= &lex->select_lex;
+    view_select->select_number= ++thd->select_number;
+
     ulong save_mode= thd->variables.sql_mode;
     /* switch off modes which can prevent normal parsing of VIEW
       - MODE_REAL_AS_FLOAT            affect only CREATE TABLE parsing
diff --git a/sql/sql_yacc.yy b/sql/sql_yacc.yy
index 0c7d2fc2187..61d78ae831a 100644
--- a/sql/sql_yacc.yy
+++ b/sql/sql_yacc.yy
@@ -104,12 +104,13 @@ const LEX_STRING null_lex_str={0,0};
 void my_parse_error(const char *s)
 {
   THD *thd= current_thd;
+  Lex_input_stream *lip= thd->m_lip;
 
-  char *yytext= (char*) thd->lex->tok_start;
+  const char *yytext= lip->tok_start;
   /* Push an error into the error stack */
   my_printf_error(ER_PARSE_ERROR,  ER(ER_PARSE_ERROR), MYF(0), s,
-                  (yytext ? (char*) yytext : ""),
-                  thd->lex->yylineno);
+                  (yytext ? yytext : ""),
+                  lip->yylineno);
 }
 
 /**
@@ -1837,7 +1838,9 @@ opt_ev_comment: /* empty */ { $$= 0; }
 
 ev_sql_stmt:
           {
-            LEX *lex= Lex;
+            THD *thd= YYTHD;
+            LEX *lex= thd->lex;
+            Lex_input_stream *lip= thd->m_lip;
 
             /*
               This stops the following :
@@ -1874,22 +1877,23 @@ ev_sql_stmt:
             bzero((char *)&lex->sp_chistics, sizeof(st_sp_chistics));
             lex->sphead->m_chistics= &lex->sp_chistics;
 
-            lex->sphead->m_body_begin= lex->ptr;
+            lex->sphead->m_body_begin= lip->ptr;
             
-            Lex->event_parse_data->body_begin= lex->ptr;
+            lex->event_parse_data->body_begin= lip->ptr;
 
           }
           ev_sql_stmt_inner
           {
-            LEX *lex=Lex;
+            THD *thd= YYTHD;
+            LEX *lex= thd->lex;
 
             /* return back to the original memory root ASAP */
-            lex->sphead->init_strings(YYTHD, lex);
-            lex->sphead->restore_thd_mem_root(YYTHD);
+            lex->sphead->init_strings(thd, lex);
+            lex->sphead->restore_thd_mem_root(thd);
 
             lex->sp_chistics.suid= SP_IS_SUID;  //always the definer!
 
-            Lex->event_parse_data->init_body(YYTHD);
+            lex->event_parse_data->init_body(thd);
           }
       ;
 
@@ -1983,7 +1987,9 @@ create_function_tail:
 	  }
 	| '('
 	  {
-	    LEX *lex= Lex;
+            THD *thd= YYTHD;
+            LEX *lex= thd->lex;
+            Lex_input_stream *lip= thd->m_lip;
 	    sp_head *sp;
 
             /* 
@@ -2003,9 +2009,9 @@ create_function_tail:
 	    }
 	    /* Order is important here: new - reset - init */
 	    sp= new sp_head();
-	    sp->reset_thd_mem_root(YYTHD);
+	    sp->reset_thd_mem_root(thd);
 	    sp->init(lex);
-            sp->init_sp_name(YYTHD, lex->spname);
+            sp->init_sp_name(thd, lex->spname);
 
 	    sp->m_type= TYPE_ENUM_FUNCTION;
 	    lex->sphead= sp;
@@ -2014,15 +2020,17 @@ create_function_tail:
 	      stored procedure, otherwise yylex will chop it into pieces
 	      at each ';'.
 	    */
-            $<ulong_num>$= YYTHD->client_capabilities & CLIENT_MULTI_QUERIES;
-	    YYTHD->client_capabilities &= ~CLIENT_MULTI_QUERIES;
-	    lex->sphead->m_param_begin= lex->tok_start+1;
+            $<ulong_num>$= thd->client_capabilities & CLIENT_MULTI_QUERIES;
+	    thd->client_capabilities &= ~CLIENT_MULTI_QUERIES;
+	    lex->sphead->m_param_begin= lip->tok_start+1;
 	  }
           sp_fdparam_list ')'
 	  {
-	    LEX *lex= Lex;
+            THD *thd= YYTHD;
+            LEX *lex= thd->lex;
+            Lex_input_stream *lip= thd->m_lip;
 
-	    lex->sphead->m_param_end= lex->tok_start;
+	    lex->sphead->m_param_end= lip->tok_start;
 	  }
 	  RETURNS_SYM
 	  {
@@ -2057,10 +2065,12 @@ create_function_tail:
 	  }
 	  sp_c_chistics
 	  {
-	    LEX *lex= Lex;
+            THD *thd= YYTHD;
+            LEX *lex= thd->lex;
+            Lex_input_stream *lip= thd->m_lip;
 
 	    lex->sphead->m_chistics= &lex->sp_chistics;
-	    lex->sphead->m_body_begin= lex->tok_start;
+	    lex->sphead->m_body_begin= lip->tok_start;
 	  }
 	  sp_proc_stmt
 	  {
@@ -2666,14 +2676,18 @@ sp_proc_stmt_if:
         
 sp_proc_stmt_statement:
 	  {
-	    LEX *lex= Lex;
+            THD *thd= YYTHD;
+            LEX *lex= thd->lex;
+            Lex_input_stream *lip= thd->m_lip;
 
-	    lex->sphead->reset_lex(YYTHD);
-	    lex->sphead->m_tmp_query= lex->tok_start;
+	    lex->sphead->reset_lex(thd);
+	    lex->sphead->m_tmp_query= lip->tok_start;
 	  }
 	  statement
 	  {
-	    LEX *lex= Lex;
+            THD *thd= YYTHD;
+            LEX *lex= thd->lex;
+            Lex_input_stream *lip= thd->m_lip;
 	    sp_head *sp= lex->sphead;
 
             sp->m_flags|= sp_get_flags_for_command(lex);
@@ -2700,15 +2714,15 @@ sp_proc_stmt_statement:
                 lex->tok_end otherwise.
               */
               if (yychar == YYEMPTY)
-                i->m_query.length= lex->ptr - sp->m_tmp_query;
+                i->m_query.length= lip->ptr - sp->m_tmp_query;
               else
-                i->m_query.length= lex->tok_end - sp->m_tmp_query;
-              i->m_query.str= strmake_root(YYTHD->mem_root,
+                i->m_query.length= lip->tok_end - sp->m_tmp_query;
+              i->m_query.str= strmake_root(thd->mem_root,
                                            sp->m_tmp_query,
                                            i->m_query.length);
               sp->add_instr(i);
             }
-	    sp->restore_lex(YYTHD);
+	    sp->restore_lex(thd);
           }
         ;
 
@@ -6212,10 +6226,18 @@ select_item:
 	  };
 
 remember_name:
-	{ $$=(char*) Lex->tok_start; };
+        {
+          THD *thd= YYTHD;
+          Lex_input_stream *lip= thd->m_lip;
+          $$= (char*) lip->tok_start;
+        };
 
 remember_end:
-	{ $$=(char*) Lex->tok_end; };
+        {
+          THD *thd= YYTHD;
+          Lex_input_stream *lip= thd->m_lip;
+          $$=(char*) lip->tok_end;
+        };
 
 select_item2:
 	table_wild	{ $$=$1; } /* table.* */
@@ -7983,12 +8005,14 @@ procedure_list2:
 procedure_item:
 	  remember_name expr
 	  {
-	    LEX *lex= Lex;
-	    if (add_proc_to_list(lex->thd, $2))
+            THD *thd= YYTHD;
+            Lex_input_stream *lip= thd->m_lip;
+
+	    if (add_proc_to_list(thd, $2))
 	      MYSQL_YYABORT;
 	    if (!$2->name)
-	      $2->set_name($1,(uint) ((char*) lex->tok_end - $1),
-                           YYTHD->charset());
+	      $2->set_name($1,(uint) ((char*) lip->tok_end - $1),
+                           thd->charset());
 	  }
           ;
 
@@ -9078,13 +9102,16 @@ use:	USE_SYM ident
 
 load:   LOAD DATA_SYM
         {
-          LEX *lex=Lex;
+          THD *thd= YYTHD;
+          LEX *lex= thd->lex;
+          Lex_input_stream *lip= thd->m_lip;
+
 	  if (lex->sphead)
 	  {
 	    my_error(ER_SP_BADSTATEMENT, MYF(0), "LOAD DATA");
 	    MYSQL_YYABORT;
 	  }
-          lex->fname_start= lex->ptr;
+          lex->fname_start= lip->ptr;
         }
         load_data
         {}
@@ -9118,8 +9145,10 @@ load_data:
         }
         opt_duplicate INTO
         {
-	  LEX *lex=Lex;
-	  lex->fname_end= lex->ptr;
+          THD *thd= YYTHD;
+          LEX *lex= thd->lex;
+          Lex_input_stream *lip= thd->m_lip;
+	  lex->fname_end= lip->ptr;
 	}
         TABLE_SYM table_ident
         {
@@ -9300,14 +9329,15 @@ param_marker:
         PARAM_MARKER
         {
           THD *thd= YYTHD;
-	  LEX *lex= thd->lex;
+          LEX *lex= thd->lex;
+          Lex_input_stream *lip= thd->m_lip;
           Item_param *item;
           if (! lex->parsing_options.allows_variable)
           {
             my_error(ER_VIEW_SELECT_VARIABLE, MYF(0));
             MYSQL_YYABORT;
           }
-          item= new Item_param((uint) (lex->tok_start - thd->query));
+          item= new Item_param((uint) (lip->tok_start - thd->query));
           if (!($$= item) || lex->param_list.push_back(item))
           {
             my_message(ER_OUT_OF_RESOURCES, ER(ER_OUT_OF_RESOURCES), MYF(0));
@@ -9330,8 +9360,11 @@ signed_literal:
 literal:
 	text_literal	{ $$ =	$1; }
 	| NUM_literal	{ $$ = $1; }
-	| NULL_SYM	{ $$ =	new Item_null();
-			  Lex->next_state=MY_LEX_OPERATOR_OR_IDENT;}
+	| NULL_SYM
+          {
+            $$ = new Item_null();
+            YYTHD->m_lip->next_state=MY_LEX_OPERATOR_OR_IDENT;
+          }
 	| FALSE_SYM	{ $$= new Item_int((char*) "FALSE",0,1); }
 	| TRUE_SYM	{ $$= new Item_int((char*) "TRUE",1,1); }
 	| HEX_NUM	{ $$ =	new Item_hex_string($1.str, $1.length);}
@@ -9421,8 +9454,10 @@ order_ident:
 simple_ident:
 	ident
 	{
+          THD *thd= YYTHD;
+          LEX *lex= thd->lex;
+          Lex_input_stream *lip= thd->m_lip;
 	  sp_variable_t *spv;
-	  LEX *lex = Lex;
           sp_pcontext *spc = lex->spcont;
 	  if (spc && (spv = spc->find_variable(&$1)))
 	  {
@@ -9435,7 +9470,7 @@ simple_ident:
 
             Item_splocal *splocal;
             splocal= new Item_splocal($1, spv->offset, spv->type,
-                                      lex->tok_start_prev - 
+                                      lip->tok_start_prev - 
                                       lex->sphead->m_tmp_query);
 #ifndef DBUG_OFF
             if (splocal)
@@ -10085,7 +10120,11 @@ option_value_list:
 
 option_type_value:
         {
-          if (Lex->sphead)
+          THD *thd= YYTHD;
+          LEX *lex= thd->lex;
+          Lex_input_stream *lip= thd->m_lip;
+
+          if (lex->sphead)
           {
             /*
               If we are in SP we want have own LEX for each assignment.
@@ -10097,9 +10136,8 @@ option_type_value:
 
               QQ: May be we should simply prohibit group assignments in SP?
             */
-            LEX *lex;
-            Lex->sphead->reset_lex(YYTHD);
-            lex= Lex;
+            lex->sphead->reset_lex(thd);
+            lex= thd->lex;
 
             /* Set new LEX as if we at start of set rule. */
 	    lex->sql_command= SQLCOM_SET_OPTION;
@@ -10107,12 +10145,14 @@ option_type_value:
 	    lex->option_type=OPT_SESSION;
 	    lex->var_list.empty();
             lex->one_shot_set= 0;
-	    lex->sphead->m_tmp_query= lex->tok_start;
+	    lex->sphead->m_tmp_query= lip->tok_start;
           }
         }
 	ext_option_value
         {
-          LEX *lex= Lex;
+          THD *thd= YYTHD;
+          LEX *lex= thd->lex;
+          Lex_input_stream *lip= thd->m_lip;
 
           if (lex->sphead)
           {
@@ -10134,15 +10174,15 @@ option_type_value:
 
               /*
                 Extract the query statement from the tokenizer.  The
-                end is either lex->ptr, if there was no lookahead,
-                lex->tok_end otherwise.
+                end is either lip->ptr, if there was no lookahead,
+                lip->tok_end otherwise.
               */
               if (yychar == YYEMPTY)
-                qbuff.length= lex->ptr - sp->m_tmp_query;
+                qbuff.length= lip->ptr - sp->m_tmp_query;
               else
-                qbuff.length= lex->tok_end - sp->m_tmp_query;
+                qbuff.length= lip->tok_end - sp->m_tmp_query;
 
-              if (!(qbuff.str= alloc_root(YYTHD->mem_root, qbuff.length + 5)))
+              if (!(qbuff.str= alloc_root(thd->mem_root, qbuff.length + 5)))
                 MYSQL_YYABORT;
 
               strmake(strmake(qbuff.str, "SET ", 4), sp->m_tmp_query,
@@ -10151,7 +10191,7 @@ option_type_value:
               i->m_query= qbuff;
               sp->add_instr(i);
             }
-            lex->sphead->restore_lex(YYTHD);
+            lex->sphead->restore_lex(thd);
           }
         };
 
@@ -11400,7 +11440,9 @@ trigger_tail:
 	TRIGGER_SYM remember_name sp_name trg_action_time trg_event
 	ON remember_name table_ident FOR_SYM remember_name EACH_SYM ROW_SYM
 	{
-	  LEX *lex= Lex;
+          THD *thd= YYTHD;
+          LEX *lex= thd->lex;
+          Lex_input_stream *lip= thd->m_lip;
 	  sp_head *sp;
 
 	  if (lex->sphead)
@@ -11411,9 +11453,9 @@ trigger_tail:
 
 	  if (!(sp= new sp_head()))
 	    MYSQL_YYABORT;
-	  sp->reset_thd_mem_root(YYTHD);
+	  sp->reset_thd_mem_root(thd);
 	  sp->init(lex);
-          sp->init_sp_name(YYTHD, $3);
+          sp->init_sp_name(thd, $3);
 	  lex->stmt_definition_begin= $2;
           lex->ident.str= $7;
           lex->ident.length= $10 - $7;
@@ -11426,12 +11468,12 @@ trigger_tail:
 	    stored procedure, otherwise yylex will chop it into pieces
 	    at each ';'.
 	  */
-	  $<ulong_num>$= YYTHD->client_capabilities & CLIENT_MULTI_QUERIES;
-	  YYTHD->client_capabilities &= ~CLIENT_MULTI_QUERIES;
+	  $<ulong_num>$= thd->client_capabilities & CLIENT_MULTI_QUERIES;
+	  thd->client_capabilities &= ~CLIENT_MULTI_QUERIES;
 
 	  bzero((char *)&lex->sp_chistics, sizeof(st_sp_chistics));
 	  lex->sphead->m_chistics= &lex->sp_chistics;
-	  lex->sphead->m_body_begin= lex->ptr;
+	  lex->sphead->m_body_begin= lip->ptr;
           while (my_isspace(system_charset_info, lex->sphead->m_body_begin[0]))
             ++lex->sphead->m_body_begin;
 	}
@@ -11510,24 +11552,30 @@ sp_tail:
 	}
         '('
 	{
-	  LEX *lex= Lex;
+          THD *thd= YYTHD;
+          LEX *lex= thd->lex;
+          Lex_input_stream *lip= thd->m_lip;
 
-	  lex->sphead->m_param_begin= lex->tok_start+1;
+	  lex->sphead->m_param_begin= lip->tok_start+1;
 	}
 	sp_pdparam_list
 	')'
 	{
-	  LEX *lex= Lex;
+          THD *thd= YYTHD;
+          LEX *lex= thd->lex;
+          Lex_input_stream *lip= thd->m_lip;
 
-	  lex->sphead->m_param_end= lex->tok_start;
+	  lex->sphead->m_param_end= lip->tok_start;
 	  bzero((char *)&lex->sp_chistics, sizeof(st_sp_chistics));
 	}
 	sp_c_chistics
 	{
-	  LEX *lex= Lex;
+          THD *thd= YYTHD;
+          LEX *lex= thd->lex;
+          Lex_input_stream *lip= thd->m_lip;
 
 	  lex->sphead->m_chistics= &lex->sp_chistics;
-	  lex->sphead->m_body_begin= lex->tok_start;
+	  lex->sphead->m_body_begin= lip->tok_start;
 	}
 	sp_proc_stmt
 	{