MDEV-6050 MySQL Bug#13036505 62540: TABLE LOCKS WITHIN STORED FUNCTIONS ARE BACK IN 5.5 WITH MIXED AND ROW BI

cherry-pick revno 4053
committer: Gopal Shankar <gopal.shankar@oracle.com>
branch nick: sf_mysql-5.6
timestamp: Fri 2012-07-20 12:25:34 +0530
message:
  Bug#13036505 62540: TABLE LOCKS WITHIN STORED FUNCTIONS ARE BACK IN
                      5.5 WITH MIXED AND ROW BI.

1 files changed, 26 insertions, 6 deletions

diff --git a/sql/sp_head.h b/sql/sp_head.h
index cc598186d08..dbdb957aa79 100644
--- a/sql/sp_head.h
+++ b/sql/sp_head.h
@@ -161,7 +161,21 @@ public:
     LOG_SLOW_STATEMENTS= 256,   // Used by events
     LOG_GENERAL_LOG= 512,        // Used by events
     HAS_SQLCOM_RESET= 1024,
-    HAS_SQLCOM_FLUSH= 2048
+    HAS_SQLCOM_FLUSH= 2048,
+
+    /**
+      Marks routines that directly (i.e. not by calling other routines)
+      change tables. Note that this flag is set automatically based on
+      type of statements used in the stored routine and is different
+      from routine characteristic provided by user in a form of CONTAINS
+      SQL, READS SQL DATA, MODIFIES SQL DATA clauses. The latter are
+      accepted by parser but pretty much ignored after that.
+      We don't rely on them:
+      a) for compatibility reasons.
+      b) because in CONTAINS SQL case they don't provide enough
+      information anyway.
+     */
+    MODIFIES_DATA= 4096
   };
 
   stored_procedure_type m_type;
@@ -332,11 +346,17 @@ public:
   int
   add_instr(sp_instr *instr);
 
-  inline uint
-  instructions()
-  {
-    return m_instr.elements;
-  }
+  /**
+    Returns true if any substatement in the routine directly
+    (not through another routine) modifies data/changes table.
+
+    @sa Comment for MODIFIES_DATA flag.
+  */
+  bool modifies_data() const
+  { return m_flags & MODIFIES_DATA; }
+
+  inline uint instructions()
+  { return m_instr.elements; }
 
   inline sp_instr *
   last_instruction()