Bug#24989: The DEADLOCK error is improperly handled by InnoDB.

When innodb detects a deadlock it calls ha_rollback_trans() to rollback the 
main transaction. But such action isn't allowed from inside of triggers and
functions. When it happen the 'Explicit or implicit commit' error is thrown
even if there is no commit/rollback statements in the trigger/function. This
leads to the user confusion.

Now the convert_error_code_to_mysql() function doesn't call the 
ha_rollback_trans() function directly but rather calls the
mark_transaction_to_rollback function and returns an error.
The sp_rcontext::find_handler() now doesn't allow errors to be caught by the
trigger/function error handlers when the thd->is_fatal_sub_stmt_error flag
is set. Procedures are still allowed to catch such errors.
The sp_rcontext::find_handler function now accepts a THD handle as a parameter.
The transaction_rollback_request and the is_fatal_sub_stmt_error flags are 
added to the THD class. The are initialized by the THD class constructor.
Now the ha_autocommit_or_rollback function rolls back main transaction
when not in a sub statement and the thd->transaction_rollback_request
is set.
The THD::restore_sub_statement_state function now resets the 
thd->is_fatal_sub_stmt_error flag on exit from a sub-statement.

mysql-test/r/innodb-big.result

@@ -32,3 +32,69 @@ select sum(id) from t3;
 sum(id)
 2199024304128
 drop table t1,t2,t3,t4;
+CREATE TABLE t1 (f1 int NOT NULL) ENGINE=InnoDB;
+CREATE TABLE t2 (f2 int(11) NOT NULL PRIMARY KEY AUTO_INCREMENT) ENGINE=InnoDB;
+CREATE TRIGGER t1_bi before INSERT
+ON t1 FOR EACH ROW
+BEGIN
+DECLARE CONTINUE HANDLER FOR SQLSTATE '40001' SET @a:= 'deadlock';
+DECLARE CONTINUE HANDLER FOR SQLEXCEPTION SET @a:= 'exception';
+INSERT INTO t2 (f2) VALUES (1);
+DELETE FROM t2 WHERE f2 = 1;
+END;|
+CREATE PROCEDURE proc24989()
+BEGIN
+DECLARE CONTINUE HANDLER FOR SQLSTATE '40001' SET @b:= 'deadlock';
+DECLARE CONTINUE HANDLER FOR SQLEXCEPTION SET @a:= 'exception';
+INSERT INTO t2 (f2) VALUES (1);
+DELETE FROM t2 WHERE f2 = 1;
+END;|
+create procedure proc24989_2()
+deterministic
+begin
+declare continue handler for sqlexception
+select 'Outer handler' as 'exception';
+insert into t1 values(1);
+select "continued";
+end|
+start transaction;
+insert into t1 values(1);
+start transaction;
+insert into t2 values(123);
+insert into t1 values(1);
+insert into t1 values(1);
+ERROR 40001: Deadlock found when trying to get lock; try restarting transaction
+select @a;
+@a
+NULL
+select * from t2;
+f2
+commit;
+start transaction;
+insert into t1 values(1);
+start transaction;
+insert into t2 values(123);
+call proc24989();
+insert into t1 values(1);
+select @a,@b;
+@a	@b
+exception	deadlock
+select * from t2;
+f2
+commit;
+start transaction;
+insert into t1 values(1);
+start transaction;
+insert into t2 values(123);
+call proc24989_2();
+insert into t1 values(1);
+commit;
+exception
+Outer handler
+continued
+continued
+select * from t2;
+f2
+drop procedure proc24989;
+drop procedure proc24989_2;
+drop table t1,t2;

mysql-test/t/innodb-big.test

@@ -44,3 +44,109 @@ INSERT INTO t3 SELECT concat(id),id from t2 ORDER BY -id;
 INSERT INTO t4 SELECT * from t3 ORDER BY concat(a);
 select sum(id) from t3;
 drop table t1,t2,t3,t4;
+
+#
+# Bug#24989: The DEADLOCK error is improperly handled by InnoDB.
+#
+CREATE TABLE t1 (f1 int NOT NULL) ENGINE=InnoDB;
+CREATE TABLE t2 (f2 int(11) NOT NULL PRIMARY KEY AUTO_INCREMENT) ENGINE=InnoDB;
+DELIMITER |;
+CREATE TRIGGER t1_bi before INSERT
+    ON t1 FOR EACH ROW
+BEGIN
+  DECLARE CONTINUE HANDLER FOR SQLSTATE '40001' SET @a:= 'deadlock';
+  DECLARE CONTINUE HANDLER FOR SQLEXCEPTION SET @a:= 'exception';
+  INSERT INTO t2 (f2) VALUES (1);
+  DELETE FROM t2 WHERE f2 = 1;
+END;|
+
+CREATE PROCEDURE proc24989()
+BEGIN
+  DECLARE CONTINUE HANDLER FOR SQLSTATE '40001' SET @b:= 'deadlock';
+  DECLARE CONTINUE HANDLER FOR SQLEXCEPTION SET @a:= 'exception';
+  INSERT INTO t2 (f2) VALUES (1);
+  DELETE FROM t2 WHERE f2 = 1;
+END;|
+
+create procedure proc24989_2()
+    deterministic
+begin
+  declare continue handler for sqlexception
+    select 'Outer handler' as 'exception';
+
+  insert into t1 values(1);
+  select "continued";
+end|
+
+DELIMITER ;|
+
+connect (con1,localhost,root,,);
+connect (con2,localhost,root,,);
+
+connection con1;
+start transaction;
+insert into t1 values(1);
+
+connection con2;
+start transaction;
+insert into t2 values(123);
+send insert into t1 values(1);
+
+connection con1;
+--sleep 1
+insert into t1 values(1);
+
+connection con2;
+--error 1213
+reap;
+select @a;
+# check that the whole transaction was rolled back
+select * from t2;
+
+connection con1;
+commit;
+start transaction;
+insert into t1 values(1);
+
+connection con2;
+start transaction;
+insert into t2 values(123);
+send call proc24989();
+
+connection con1;
+--sleep 1
+insert into t1 values(1);
+
+connection con2;
+reap;
+select @a,@b;
+# check that the whole transaction was rolled back
+select * from t2;
+
+connection con1;
+commit;
+start transaction;
+insert into t1 values(1);
+
+connection con2;
+start transaction;
+insert into t2 values(123);
+send call proc24989_2();
+
+connection con1;
+--sleep 1
+insert into t1 values(1);
+commit;
+
+connection con2;
+reap;
+# check that the whole transaction was rolled back
+select * from t2;
+
+disconnect con1;
+disconnect con2;
+connection default;
+drop procedure proc24989;
+drop procedure proc24989_2;
+drop table t1,t2;
+

sql/ha_innodb.cc

@@ -455,9 +455,7 @@ convert_error_code_to_mysql(
  		tell it also to MySQL so that MySQL knows to empty the
  		cached binlog for this transaction */
 
- 		if (thd) {
- 			ha_rollback(thd);
- 		}
+                mark_transaction_to_rollback(thd, TRUE);
 
     		return(HA_ERR_LOCK_DEADLOCK);
 
@@ -467,9 +465,7 @@ convert_error_code_to_mysql(
 		latest SQL statement in a lock wait timeout. Previously, we
 		rolled back the whole transaction. */
 
-		if (thd && row_rollback_on_timeout) {
-			ha_rollback(thd);
-		}
+                mark_transaction_to_rollback(thd, row_rollback_on_timeout);
 
    		return(HA_ERR_LOCK_WAIT_TIMEOUT);
 
@@ -521,9 +517,7 @@ convert_error_code_to_mysql(
  		tell it also to MySQL so that MySQL knows to empty the
  		cached binlog for this transaction */
 
- 		if (thd) {
- 			ha_rollback(thd);
- 		}
+                mark_transaction_to_rollback(thd, TRUE);
 
     		return(HA_ERR_LOCK_TABLE_FULL);
     	} else {

sql/handler.cc

@@ -821,6 +821,9 @@ int ha_rollback_trans(THD *thd, bool all)
     }
   }
 #endif /* USING_TRANSACTIONS */
+  if (all)
+    thd->transaction_rollback_request= FALSE;
+
   /*
     If a non-transactional table was updated, warn; don't warn if this is a
     slave thread (because when a slave thread executes a ROLLBACK, it has
@@ -858,6 +861,8 @@ int ha_autocommit_or_rollback(THD *thd, int error)
       if (ha_commit_stmt(thd))
 	error=1;
     }
+    else if (thd->transaction_rollback_request && !thd->in_sub_stmt)
+      (void) ha_rollback(thd);
     else
       (void) ha_rollback_stmt(thd);
 

sql/sp_rcontext.cc

@@ -37,6 +37,7 @@ sp_rcontext::sp_rcontext(sp_pcontext *root_parsing_ctx,
    m_var_items(0),
    m_return_value_fld(return_value_fld),
    m_return_value_set(FALSE),
+   in_sub_stmt(FALSE),
    m_hcount(0),
    m_hsp(0),
    m_ihsp(0),
@@ -67,6 +68,8 @@ sp_rcontext::~sp_rcontext()
 
 bool sp_rcontext::init(THD *thd)
 {
+  in_sub_stmt= thd->in_sub_stmt;
+
   if (init_var_table(thd) || init_var_items())
     return TRUE;
 
@@ -191,7 +194,7 @@ sp_rcontext::set_return_value(THD *thd, Item **return_value_item)
 */
 
 bool
-sp_rcontext::find_handler(uint sql_errno,
+sp_rcontext::find_handler(THD *thd, uint sql_errno,
                           MYSQL_ERROR::enum_warning_level level)
 {
   if (m_hfound >= 0)
@@ -200,6 +203,15 @@ sp_rcontext::find_handler(uint sql_errno,
   const char *sqlstate= mysql_errno_to_sqlstate(sql_errno);
   int i= m_hcount, found= -1;
 
+  /*
+    If this is a fatal sub-statement error, and this runtime
+    context corresponds to a sub-statement, no CONTINUE/EXIT
+    handlers from this context are applicable: try to locate one
+    in the outer scope.
+  */
+  if (thd->is_fatal_sub_stmt_error && in_sub_stmt)
+    i= 0;
+
   /* Search handlers from the latest (innermost) to the oldest (outermost) */
   while (i--)
   {
@@ -252,7 +264,7 @@ sp_rcontext::find_handler(uint sql_errno,
     */
     if (m_prev_runtime_ctx && IS_EXCEPTION_CONDITION(sqlstate) &&
         level == MYSQL_ERROR::WARN_LEVEL_ERROR)
-      return m_prev_runtime_ctx->find_handler(sql_errno, level);
+      return m_prev_runtime_ctx->find_handler(thd, sql_errno, level);
     return FALSE;
   }
   m_hfound= found;
@@ -298,7 +310,7 @@ sp_rcontext::handle_error(uint sql_errno,
     elevated_level= MYSQL_ERROR::WARN_LEVEL_ERROR;
   }
 
-  if (find_handler(sql_errno, elevated_level))
+  if (find_handler(thd, sql_errno, elevated_level))
   {
     if (elevated_level == MYSQL_ERROR::WARN_LEVEL_ERROR)
     {

sql/sp_rcontext.h

@@ -125,7 +125,7 @@ class sp_rcontext : public Sql_alloc
 
   // Returns 1 if a handler was found, 0 otherwise.
   bool
-  find_handler(uint sql_errno,MYSQL_ERROR::enum_warning_level level);
+  find_handler(THD *thd, uint sql_errno,MYSQL_ERROR::enum_warning_level level);
 
   // If there is an error handler for this error, handle it and return TRUE.
   bool
@@ -236,6 +236,10 @@ private:
     during execution.
   */
   bool m_return_value_set;
+  /**
+    TRUE if the context is created for a sub-statement.
+  */
+  bool in_sub_stmt;
 
   sp_handler_t *m_handler;      // Visible handlers
   uint m_hcount;                // Stack pointer for m_handler

sql/sql_class.cc

@@ -173,6 +173,7 @@ THD::THD()
    Open_tables_state(refresh_version),
    lock_id(&main_lock_id),
    user_time(0), in_sub_stmt(0), global_read_lock(0), is_fatal_error(0),
+   transaction_rollback_request(0), is_fatal_sub_stmt_error(0),
    rand_used(0), time_zone_used(0),
    last_insert_id_used(0), last_insert_id_used_bin_log(0), insert_id_used(0),
    clear_next_insert_id(0), in_lock_tables(0), bootstrap(0),
@@ -967,7 +968,7 @@ void select_send::abort()
 {
   DBUG_ENTER("select_send::abort");
   if (status && thd->spcont &&
-      thd->spcont->find_handler(thd->net.last_errno,
+      thd->spcont->find_handler(thd, thd->net.last_errno,
                                 MYSQL_ERROR::WARN_LEVEL_ERROR))
   {
     /*
@@ -2150,6 +2151,13 @@ void THD::restore_sub_statement_state(Sub_statement_state *backup)
   limit_found_rows= backup->limit_found_rows;
   sent_row_count=   backup->sent_row_count;
   client_capabilities= backup->client_capabilities;
+  /*
+    If we've left sub-statement mode, reset the fatal error flag.
+    Otherwise keep the current value, to propagate it up the sub-statement
+    stack.
+  */
+  if (!in_sub_stmt)
+    is_fatal_sub_stmt_error= FALSE;
 
   if ((options & OPTION_BIN_LOG) && is_update_query(lex->sql_command))
     mysql_bin_log.stop_union_events(this);
@@ -2163,6 +2171,18 @@ void THD::restore_sub_statement_state(Sub_statement_state *backup)
 }
 
 
+/**
+  Mark transaction to rollback and mark error as fatal to a sub-statement.
+
+  @param  thd   Thread handle
+  @param  all   TRUE <=> rollback main transaction.
+*/
+
+void mark_transaction_to_rollback(THD *thd, bool all)
+{
+  thd->is_fatal_sub_stmt_error= TRUE;
+  thd->transaction_rollback_request= all;
+}
 /***************************************************************************
   Handling of XA id cacheing
 ***************************************************************************/

sql/sql_class.h

@@ -1406,7 +1406,33 @@ public:
   bool       slave_thread, one_shot_set;
   bool	     locked, some_tables_deleted;
   bool       last_cuted_field;
-  bool	     no_errors, password, is_fatal_error;
+  bool	     no_errors, password;
+  /**
+    Set to TRUE if execution of the current compound statement
+    can not continue. In particular, disables activation of
+    CONTINUE or EXIT handlers of stored routines.
+    Reset in the end of processing of the current user request, in
+    @see mysql_reset_thd_for_next_command().
+  */
+  bool is_fatal_error;
+  /**
+    Set by a storage engine to request the entire
+    transaction (that possibly spans multiple engines) to
+    rollback. Reset in ha_rollback.
+  */
+  bool       transaction_rollback_request;
+  /**
+    TRUE if we are in a sub-statement and the current error can
+    not be safely recovered until we left the sub-statement mode.
+    In particular, disables activation of CONTINUE and EXIT
+    handlers inside sub-statements. E.g. if it is a deadlock
+    error and requires a transaction-wide rollback, this flag is
+    raised (traditionally, MySQL first has to close all the reads
+    via @see handler::ha_index_or_rnd_end() and only then perform
+    the rollback).
+    Reset to FALSE when we leave the sub-statement mode.
+  */
+  bool       is_fatal_sub_stmt_error;
   bool	     query_start_used, rand_used, time_zone_used;
 
   /*
@@ -2338,3 +2364,5 @@ public:
 /* Functions in sql_class.cc */
 
 void add_to_status(STATUS_VAR *to_var, STATUS_VAR *from_var);
+void mark_transaction_to_rollback(THD *thd, bool all);
+