Give error if locked table is used twice in query. This fixes strange error...

Give error if locked table is used twice in query. This fixes strange error message when doing LOCK TABLES t1 WRITE; INSERT TABLE t1 SELECT * from t1 (Bug #2296)

client/mysqldump.c

@@ -154,7 +154,7 @@ static struct my_option my_long_options[] =
   {"first-slave", 'x', "Locks all tables across all databases.",
    (gptr*) &opt_first_slave, (gptr*) &opt_first_slave, 0, GET_BOOL, NO_ARG,
    0, 0, 0, 0, 0, 0},
-  {"flush-logs", 'F', "Flush logs file in server before starting dump.",
+  {"flush-logs", 'F', "Flush logs file in server before starting dump. Note that if you use this option in combination with the --all-databases (or -A) option, the logs will be flushed for each database dumped.",
    (gptr*) &flush_logs, (gptr*) &flush_logs, 0, GET_BOOL, NO_ARG, 0, 0, 0, 0,
    0, 0},
   {"force", 'f', "Continue even if we get an sql-error.",

mysql-test/r/lock.result

@@ -41,5 +41,9 @@ lock tables t1 write;
 check table t2;
 Table	Op	Msg_type	Msg_text
 test.t2	check	error	Table 't2' was not locked with LOCK TABLES
+insert into t1 select nr from t1;
+Table 't1' was not locked with LOCK TABLES
 unlock tables;
+lock tables t1 write, t1 as t1_alias read;
+insert into t1 select index1,nr from t1 as t1_alias;
 drop table t1,t2;

mysql-test/t/lock.test

@@ -51,5 +51,9 @@ check table t1;
 # Check error message
 lock tables t1 write;
 check table t2;
+--error 1100
+insert into t1 select nr from t1;
 unlock tables;
+lock tables t1 write, t1 as t1_alias read;
+insert into t1 select index1,nr from t1 as t1_alias;
 drop table t1,t2;

sql/sql_base.cc

@@ -824,8 +824,12 @@ TABLE *open_table(THD *thd,const char *db,const char *table_name,
     {
       if (table->key_length == key_length &&
 	  !memcmp(table->table_cache_key,key,key_length) &&
-	  !my_strcasecmp(table->table_name,alias))
+	  !my_strcasecmp(table->table_name,alias) &&
+	  table->query_id != thd->query_id)
+      {
+	table->query_id=thd->query_id;
 	goto reset;
+      }
     }
     my_printf_error(ER_TABLE_NOT_LOCKED,ER(ER_TABLE_NOT_LOCKED),MYF(0),alias);
     DBUG_RETURN(0);