(pushing for Andrei)

Bug #27417 thd->no_trans_update.stmt lost value inside of SF-exec-stack
  
Once had been set the flag might later got reset inside of a stored routine 
execution stack.
The reason was in that there was no check if a new statement started at time 
of resetting.
The artifact affects most of binlogable DML queries. Notice, that multi-update 
is wrapped up within
  bug@27716 fix, multi-delete bug@29136.
  
Fixed with saving parent's statement flag of whether the statement modified 
non-transactional table, and unioning (merging) the value with that was gained 
in mysql_execute_command.
  
Resettling thd->no_trans_update members into thd->transaction.`member`;
Asserting code;
Effectively the following properties are held.
  
1. At the end of a substatement thd->transaction.stmt.modified_non_trans_table
   reflects the fact if such a table got modified by the substatement.
   That also respects THD::really_abort_on_warnin() requirements.
2. Eventually thd->transaction.stmt.modified_non_trans_table will be computed as
   the union of the values of all invoked sub-statements.
   That fixes this bug#27417;

Computing of thd->transaction.all.modified_non_trans_table is refined to base to 
the stmt's value for all the case including insert .. select statement which 
before the patch had an extra issue bug@28960.
Minor issues are covered with mysql_load, mysql_delete, and binloggin of insert in
to temp_table select. 
  
The supplied test verifies limitely, mostly asserts. The ultimate testing is defered
for bug@13270, bug@23333.

1 files changed, 29 insertions, 0 deletions

diff --git a/sql/handler.h b/sql/handler.h
index a3767573178..c44d7c7f846 100644
--- a/sql/handler.h
+++ b/sql/handler.h
@@ -420,6 +420,35 @@ typedef struct st_thd_trans
   bool        no_2pc;
   /* storage engines that registered themselves for this transaction */
   handlerton *ht[MAX_HA];
+  /* 
+    The purpose of this flag is to keep track of non-transactional
+    tables that were modified in scope of:
+    - transaction, when the variable is a member of
+    THD::transaction.all
+    - top-level statement or sub-statement, when the variable is a
+    member of THD::transaction.stmt
+    This member has the following life cycle:
+    * stmt.modified_non_trans_table is used to keep track of
+    modified non-transactional tables of top-level statements. At
+    the end of the previous statement and at the beginning of the session,
+    it is reset to FALSE.  If such functions
+    as mysql_insert, mysql_update, mysql_delete etc modify a
+    non-transactional table, they set this flag to TRUE.  At the
+    end of the statement, the value of stmt.modified_non_trans_table 
+    is merged with all.modified_non_trans_table and gets reset.
+    * all.modified_non_trans_table is reset at the end of transaction
+    
+    * Since we do not have a dedicated context for execution of a
+    sub-statement, to keep track of non-transactional changes in a
+    sub-statement, we re-use stmt.modified_non_trans_table. 
+    At entrance into a sub-statement, a copy of the value of
+    stmt.modified_non_trans_table (containing the changes of the
+    outer statement) is saved on stack. Then 
+    stmt.modified_non_trans_table is reset to FALSE and the
+    substatement is executed. Then the new value is merged with the
+    saved value.
+  */
+  bool modified_non_trans_table;
 } THD_TRANS;
 
 enum enum_tx_isolation { ISO_READ_UNCOMMITTED, ISO_READ_COMMITTED,