take into account table lock mode when opening table:

try to find most suitable table, to avouid pickup table with too low locking mode or occupy table with write mode for select when it will be need for update later
(BUG#9597)

3 files changed, 63 insertions, 4 deletions

diff --git a/mysql-test/r/view.result b/mysql-test/r/view.result
index ef40a408932..684c4950acd 100644
--- a/mysql-test/r/view.result
+++ b/mysql-test/r/view.result
@@ -1977,3 +1977,17 @@ A
 B
 DROP VIEW v1;
 DROP TABLE t1;
+CREATE TABLE t1 ( bug_table_seq   INTEGER NOT NULL);
+CREATE OR REPLACE VIEW v1 AS SELECT * from t1;
+DROP PROCEDURE IF EXISTS p1;
+Warnings:
+Note	1305	PROCEDURE p1 does not exist
+CREATE PROCEDURE p1 ( )
+BEGIN
+DO (SELECT  @next := IFNULL(max(bug_table_seq),0) + 1 FROM v1);
+INSERT INTO t1 VALUES (1);
+END //
+CALL p1();
+DROP PROCEDURE p1;
+DROP VIEW v1;
+DROP TABLE t1;
diff --git a/mysql-test/t/view.test b/mysql-test/t/view.test
index d296d5ebee5..8eeac41efcd 100644
--- a/mysql-test/t/view.test
+++ b/mysql-test/t/view.test
@@ -1804,7 +1804,6 @@ drop table t1;
 #
 # Test for bug #11771: wrong query_id in SELECT * FROM <view>
 #
-
 CREATE TABLE t1 (f1 char) ENGINE = innodb;
 INSERT INTO t1 VALUES ('A');
 CREATE VIEW  v1 AS SELECT * FROM t1;
@@ -1815,3 +1814,21 @@ SELECT * FROM t1;
 
 DROP VIEW v1;
 DROP TABLE t1;
+
+#
+# opening table in correct locking mode (BUG#9597)
+#
+CREATE TABLE t1 ( bug_table_seq   INTEGER NOT NULL);
+CREATE OR REPLACE VIEW v1 AS SELECT * from t1;
+DROP PROCEDURE IF EXISTS p1;
+delimiter //;
+CREATE PROCEDURE p1 ( )
+BEGIN
+        DO (SELECT  @next := IFNULL(max(bug_table_seq),0) + 1 FROM v1);
+        INSERT INTO t1 VALUES (1);
+END //
+delimiter ;//
+CALL p1();
+DROP PROCEDURE p1;
+DROP VIEW v1;
+DROP TABLE t1;
diff --git a/sql/sql_base.cc b/sql/sql_base.cc
index 2ee1c8c24cc..7021f61a052 100644
--- a/sql/sql_base.cc
+++ b/sql/sql_base.cc
@@ -1041,6 +1041,8 @@ TABLE *open_table(THD *thd, TABLE_LIST *table_list, MEM_ROOT *mem_root,
 
   if (thd->locked_tables || thd->prelocked_mode)
   {						// Using table locks
+    TABLE *best_table= 0;
+    int best_distance= INT_MIN, distance;
     for (table=thd->open_tables; table ; table=table->next)
     {
       if (table->s->key_length == key_length &&
@@ -1049,11 +1051,37 @@ TABLE *open_table(THD *thd, TABLE_LIST *table_list, MEM_ROOT *mem_root,
           table->query_id != thd->query_id && /* skip tables already used by this query */
           !(thd->prelocked_mode && table->query_id))
       {
-        table->query_id= thd->query_id;
-        DBUG_PRINT("info",("Using locked table"));
-	goto reset;
+        distance= ((int) table->reginfo.lock_type -
+                   (int) table_list->lock_type);
+        /*
+          Find a table that either has the exact lock type requested,
+          or has the best suitable lock. In case there is no locked
+          table that has an equal or higher lock than requested,
+          we still maitain the best_table to produce an error message
+          about wrong lock mode on the table. The best_table is changed
+          if bd < 0 <= d or bd < d < 0 or 0 <= d < bd.
+
+          distance <  0 - we have not enough high lock mode
+          distance >  0 - we have lock mode higher then we require
+          distance == 0 - we have lock mode exactly which we need
+        */
+        if (best_distance < 0 && distance > best_distance ||
+            distance >= 0 && distance < best_distance)
+        {
+          best_distance= distance;
+          best_table= table;
+          if (best_distance == 0)
+            break;
+        }
       }
     }
+    if (best_table)
+    {
+      table= best_table;
+      table->query_id= thd->query_id;
+      DBUG_PRINT("info",("Using locked table"));
+      goto reset;
+    }
     /*
       is it view?
       (it is work around to allow to open view with locked tables,