A fix and a test case for Bug#10760 and complementary cleanups.

The idea of the patch
is that every cursor gets its own lock id for table level locking.
Thus cursors are protected from updates performed within the same 
connection. Additionally a list of transient (must be closed at
commit) cursors is maintained and all transient cursors are closed
when necessary. Lastly, this patch adds support for deadlock
timeouts to TLL locking when using cursors.
+ post-review fixes.


include/thr_lock.h:
  - add a notion of lock owner to table level locking. When using
    cursors, lock owner can not be identified by a thread id any more, 
    as we must protect cursors from updates issued within the same 
    connection (thread). So, each cursor has its own lock identifier to 
    use with table level locking.
  - extend return values of thr_lock and thr_multi_lock with
    THR_LOCK_TIMEOUT and THR_LOCK_DEADLOCK, since these conditions
    are now possible (see comments to thr_lock.c)
mysys/thr_lock.c:
  Better support for cursors:
  - use THR_LOCK_OWNER * as lock identifier, not pthread_t.
  - check and return an error for a trivial deadlock case, when an
    update statement is issued to a table locked by a cursor which has 
    been previously opened in the same connection.
  - add support for locking timeouts: with use of cursors, trivial 
    deadlocks can occur. For now the only remedy is the lock wait timeout,
    which is initialized from a new global variable 'table_lock_wait_timeout'
    Example of a deadlock (assuming the storage engine does not downgrade 
    locks):
    con1: open cursor for select * from t1;
    con2: open cursor for select * from t2;
    con1: update t2 set id=id*2;  -- blocked
    con2: update t1 set id=id*2;  -- deadlock
    Lock timeouts are active only if a connection is using cursors.
  - the check in the wait_for_lock loop has been changed from
    data->cond != cond to data->cond != 0. data->cond is zeroed
    in every place it's changed. 
  - added comments
sql/examples/ha_archive.cc:
  - extend the handlerton with the info about cursor behaviour at commit.
sql/examples/ha_archive.h:
  - ctor moved to .cc to make use of archive handlerton
sql/examples/ha_example.cc:
  - add handlerton instance, init handler::ht with it
sql/examples/ha_example.h:
  - ctor moved to .cc to make use of ha_example handlerton
sql/examples/ha_tina.cc:
  - add handlerton instance, init handler::ht with it
sql/examples/ha_tina.h:
  - ctor moved to .cc to make use of CSV handlerton
sql/ha_berkeley.cc:
  - init handlerton::flags and handler::ht
sql/ha_berkeley.h:
  - ctor moved to .cc to make use of BerkeleyDB handlerton
sql/ha_blackhole.cc:
  - add handlerton instance, init handler::ht with it
sql/ha_blackhole.h:
  - ctor moved to .cc to make use of blackhole handlerton
sql/ha_federated.cc:
  - add handlerton instance, init handler::ht with it
sql/ha_federated.h:
  - ctor moved to .cc to make use of federated handlerton
sql/ha_heap.cc:
  - add handlerton instance, init handler::ht with it
sql/ha_heap.h:
  - ctor moved to .cc to make use of ha_heap handlerton
sql/ha_innodb.cc:
  - init handlerton::flags and handler::ht of innobase storage engine
sql/ha_innodb.h:
  - ctor moved to .cc to make use of archive handlerton
sql/ha_myisam.cc:
  - add handlerton instance, init handler::ht with it
sql/ha_myisam.h:
  - ctor moved to .cc to make use of MyISAM handlerton
sql/ha_myisammrg.cc:
  - init handler::ht in the ctor
sql/ha_myisammrg.h:
  - ctor moved to .cc to make use of MyISAM MERGE handlerton
sql/ha_ndbcluster.cc:
  - init handlerton::flags and handler::ht
sql/handler.cc:
  - drop support for ISAM storage engine, which was removed from 5.0
  - close all "transient" cursors at COMMIT/ROLLBACK. A "transient"
    SQL level cursor is a cursor that uses tables that have a transaction-
    specific state.
sql/handler.h:
  - extend struct handlerton with flags, add handlerton *ht to every
    handler instance.
sql/lock.cc:
  - extend mysql_lock_tables to send error to the client if 
    thr_multi_lock returns a timeout or a deadlock error.
sql/mysqld.cc:
  - add server option --table_lock_wait_timeout (in seconds)
sql/set_var.cc:
  - add new global variable 'table_lock_wait_timeout' to specify
  a wait timeout for table-level locks of MySQL (in seconds). The default
  timeout is 50 seconds. The timeout is active only if the connection
  has open cursors.
sql/sql_class.cc:
  - implement Statement_map::close_transient_cursors
  - safety suggests that we need an assert ensuring 
   llock_info->n_cursors is functioning properly, adjust destruction of
   the Statement_map to allow such assert in THD::~THD
sql/sql_class.h:
  - add support for Cursors registry to Statement map.
sql/sql_prepare.cc:
  - maintain a list of cursors that must be closed at commit/rollback.
sql/sql_select.cc:
  - extend class Cursor to support specific at-COMMIT/ROLLBACK behavior.
  If a cursor uses tables of a storage engine that 
  invalidates all open tables at COMMIT/ROLLBACK, it must be closed
  before COMMIT/ROLLBACK is executed.
sql/sql_select.h:
  - add an own lock_id and commit/rollback status flag to class Cursor
tests/mysql_client_test.c:
  A test case for Bug#10760 and complementary issues: test a simple
  deadlock case too.
mysql-test/var:
  New BitKeeper file ``mysql-test/var''

34 files changed, 671 insertions, 147 deletions

diff --git a/include/thr_lock.h b/include/thr_lock.h
index dc4f9968cb7..8c6540d83e2 100644
--- a/include/thr_lock.h
+++ b/include/thr_lock.h
@@ -62,17 +62,45 @@ enum thr_lock_type { TL_IGNORE=-1,
 		     /* Abort new lock request with an error */
 		     TL_WRITE_ONLY};
 
+enum enum_thr_lock_result { THR_LOCK_SUCCESS= 0, THR_LOCK_ABORTED= 1,
+                            THR_LOCK_WAIT_TIMEOUT= 2, THR_LOCK_DEADLOCK= 3 };
+
+
 extern ulong max_write_lock_count;
+extern ulong table_lock_wait_timeout;
 extern my_bool thr_lock_inited;
 extern enum thr_lock_type thr_upgraded_concurrent_insert_lock;
 
-typedef struct st_thr_lock_data {
+/*
+  A description of the thread which owns the lock. The address
+  of an instance of this structure is used to uniquely identify the thread.
+*/
+
+typedef struct st_thr_lock_info
+{
   pthread_t thread;
+  ulong thread_id;
+  ulong n_cursors;
+} THR_LOCK_INFO;
+
+/*
+  Lock owner identifier. Globally identifies the lock owner within the
+  thread and among all the threads. The address of an instance of this
+  structure is used as id.
+*/
+
+typedef struct st_thr_lock_owner
+{
+  THR_LOCK_INFO *info;
+} THR_LOCK_OWNER;
+
+
+typedef struct st_thr_lock_data {
+  THR_LOCK_OWNER *owner;
   struct st_thr_lock_data *next,**prev;
   struct st_thr_lock *lock;
   pthread_cond_t *cond;
   enum thr_lock_type type;
-  ulong thread_id;
   void *status_param;			/* Param to status functions */
   void *debug_print_param;
 } THR_LOCK_DATA;
@@ -102,13 +130,18 @@ extern LIST *thr_lock_thread_list;
 extern pthread_mutex_t THR_LOCK_lock;
 
 my_bool init_thr_lock(void);		/* Must be called once/thread */
+#define thr_lock_owner_init(owner, info_arg) (owner)->info= (info_arg)
+void thr_lock_info_init(THR_LOCK_INFO *info);
 void thr_lock_init(THR_LOCK *lock);
 void thr_lock_delete(THR_LOCK *lock);
 void thr_lock_data_init(THR_LOCK *lock,THR_LOCK_DATA *data,
 			void *status_param);
-int thr_lock(THR_LOCK_DATA *data,enum thr_lock_type lock_type);
+enum enum_thr_lock_result thr_lock(THR_LOCK_DATA *data,
+                                   THR_LOCK_OWNER *owner,
+                                   enum thr_lock_type lock_type);
 void thr_unlock(THR_LOCK_DATA *data);
-int thr_multi_lock(THR_LOCK_DATA **data,uint count);
+enum enum_thr_lock_result thr_multi_lock(THR_LOCK_DATA **data,
+                                         uint count, THR_LOCK_OWNER *owner);
 void thr_multi_unlock(THR_LOCK_DATA **data,uint count);
 void thr_abort_locks(THR_LOCK *lock);
 void thr_abort_locks_for_thread(THR_LOCK *lock, pthread_t thread);
diff --git a/mysys/thr_lock.c b/mysys/thr_lock.c
index 85a2b34b851..b12f8234c26 100644
--- a/mysys/thr_lock.c
+++ b/mysys/thr_lock.c
@@ -84,6 +84,7 @@ multiple read locks.
 
 my_bool thr_lock_inited=0;
 ulong locks_immediate = 0L, locks_waited = 0L;
+ulong table_lock_wait_timeout;
 enum thr_lock_type thr_upgraded_concurrent_insert_lock = TL_WRITE;
 
 /* The following constants are only for debug output */
@@ -109,25 +110,32 @@ my_bool init_thr_lock()
   return 0;
 }
 
+static inline my_bool
+thr_lock_owner_equal(THR_LOCK_OWNER *rhs, THR_LOCK_OWNER *lhs)
+{
+  return rhs == lhs;
+}
+
+
 #ifdef EXTRA_DEBUG
 #define MAX_FOUND_ERRORS	10		/* Report 10 first errors */
 static uint found_errors=0;
 
 static int check_lock(struct st_lock_list *list, const char* lock_type,
-		      const char *where, my_bool same_thread, bool no_cond)
+		      const char *where, my_bool same_owner, bool no_cond)
 {
   THR_LOCK_DATA *data,**prev;
   uint count=0;
-  pthread_t first_thread;
-  LINT_INIT(first_thread);
+  THR_LOCK_OWNER *first_owner;
+  LINT_INIT(first_owner);
 
   prev= &list->data;
   if (list->data)
   {
     enum thr_lock_type last_lock_type=list->data->type;
 
-    if (same_thread && list->data)
-      first_thread=list->data->thread;
+    if (same_owner && list->data)
+      first_owner= list->data->owner;
     for (data=list->data; data && count++ < MAX_LOCKS ; data=data->next)
     {
       if (data->type != last_lock_type)
@@ -139,7 +147,8 @@ static int check_lock(struct st_lock_list *list, const char* lock_type,
 		count, lock_type, where);
 	return 1;
       }
-      if (same_thread && ! pthread_equal(data->thread,first_thread) &&
+      if (same_owner &&
+          !thr_lock_owner_equal(data->owner, first_owner) &&
 	  last_lock_type != TL_WRITE_ALLOW_WRITE)
       {
 	fprintf(stderr,
@@ -255,8 +264,8 @@ static void check_locks(THR_LOCK *lock, const char *where,
 	}
 	if (lock->read.data)
 	{
-	  if (!pthread_equal(lock->write.data->thread,
-			     lock->read.data->thread) &&
+          if (!thr_lock_owner_equal(lock->write.data->owner,
+                                    lock->read.data->owner) &&
 	      ((lock->write.data->type > TL_WRITE_DELAYED &&
 		lock->write.data->type != TL_WRITE_ONLY) ||
 	       ((lock->write.data->type == TL_WRITE_CONCURRENT_INSERT ||
@@ -330,24 +339,32 @@ void thr_lock_delete(THR_LOCK *lock)
   DBUG_VOID_RETURN;
 }
 
+
+void thr_lock_info_init(THR_LOCK_INFO *info)
+{
+  info->thread= pthread_self();
+  info->thread_id= my_thread_id();              /* for debugging */
+  info->n_cursors= 0;
+}
+
 	/* Initialize a lock instance */
 
 void thr_lock_data_init(THR_LOCK *lock,THR_LOCK_DATA *data, void *param)
 {
   data->lock=lock;
   data->type=TL_UNLOCK;
-  data->thread=pthread_self();
-  data->thread_id=my_thread_id();		/* for debugging */
+  data->owner= 0;                               /* no owner yet */
   data->status_param=param;
   data->cond=0;
 }
 
 
-static inline my_bool have_old_read_lock(THR_LOCK_DATA *data,pthread_t thread)
+static inline my_bool
+have_old_read_lock(THR_LOCK_DATA *data, THR_LOCK_OWNER *owner)
 {
   for ( ; data ; data=data->next)
   {
-    if ((pthread_equal(data->thread,thread)))
+    if (thr_lock_owner_equal(data->owner, owner))
       return 1;					/* Already locked by thread */
   }
   return 0;
@@ -365,12 +382,16 @@ static inline my_bool have_specific_lock(THR_LOCK_DATA *data,
 }
 
 
-static my_bool wait_for_lock(struct st_lock_list *wait, THR_LOCK_DATA *data,
-			     my_bool in_wait_list)
+static enum enum_thr_lock_result
+wait_for_lock(struct st_lock_list *wait, THR_LOCK_DATA *data,
+              my_bool in_wait_list)
 {
-  pthread_cond_t *cond=get_cond();
-  struct st_my_thread_var *thread_var=my_thread_var;
-  int result;
+  struct st_my_thread_var *thread_var= my_thread_var;
+  pthread_cond_t *cond= &thread_var->suspend;
+  struct timeval now;
+  struct timespec wait_timeout;
+  enum enum_thr_lock_result result= THR_LOCK_ABORTED;
+  my_bool can_deadlock= test(data->owner->info->n_cursors);
 
   if (!in_wait_list)
   {
@@ -382,31 +403,56 @@ static my_bool wait_for_lock(struct st_lock_list *wait, THR_LOCK_DATA *data,
   /* Set up control struct to allow others to abort locks */
   thread_var->current_mutex= &data->lock->mutex;
   thread_var->current_cond=  cond;
+  data->cond= cond;
 
-  data->cond=cond;
+  if (can_deadlock)
+  {
+    gettimeofday(&now, 0);
+    wait_timeout.tv_sec= now.tv_sec + table_lock_wait_timeout;
+    wait_timeout.tv_nsec= now.tv_usec * 1000;
+  }
   while (!thread_var->abort || in_wait_list)
   {
-    pthread_cond_wait(cond,&data->lock->mutex);
-    if (data->cond != cond)
+    int rc= can_deadlock ? pthread_cond_timedwait(cond, &data->lock->mutex,
+                                                  &wait_timeout) :
+                           pthread_cond_wait(cond, &data->lock->mutex);
+    /*
+      We must break the wait if one of the following occurs:
+      - the connection has been aborted (!thread_var->abort), but
+        this is not a delayed insert thread (in_wait_list). For a delayed
+        insert thread the proper action at shutdown is, apparently, to
+        acquire the lock and complete the insert.
+      - the lock has been granted (data->cond is set to NULL by the granter),
+        or the waiting has been aborted (additionally data->type is set to
+        TL_UNLOCK).
+      - the wait has timed out (rc == ETIMEDOUT)
+      Order of checks below is important to not report about timeout
+      if the predicate is true.
+    */
+    if (data->cond == 0)
+      break;
+    if (rc == ETIMEDOUT)
+    {
+      result= THR_LOCK_WAIT_TIMEOUT;
       break;
+    }
   }
 
   if (data->cond || data->type == TL_UNLOCK)
   {
-    if (data->cond)				/* aborted */
+    if (data->cond)                             /* aborted or timed out */
     {
       if (((*data->prev)=data->next))		/* remove from wait-list */
 	data->next->prev= data->prev;
       else
 	wait->last=data->prev;
+      data->type= TL_UNLOCK;                    /* No lock */
     }
-    data->type=TL_UNLOCK;			/* No lock */
-    result=1;					/* Didn't get lock */
     check_locks(data->lock,"failed wait_for_lock",0);
   }
   else
   {
-    result=0;
+    result= THR_LOCK_SUCCESS;
     statistic_increment(locks_waited, &THR_LOCK_lock);
     if (data->lock->get_status)
       (*data->lock->get_status)(data->status_param, 0);
@@ -423,20 +469,24 @@ static my_bool wait_for_lock(struct st_lock_list *wait, THR_LOCK_DATA *data,
 }
 
 
-int thr_lock(THR_LOCK_DATA *data,enum thr_lock_type lock_type)
+enum enum_thr_lock_result
+thr_lock(THR_LOCK_DATA *data, THR_LOCK_OWNER *owner,
+         enum thr_lock_type lock_type)
 {
   THR_LOCK *lock=data->lock;
-  int result=0;
+  enum enum_thr_lock_result result= THR_LOCK_SUCCESS;
+  struct st_lock_list *wait_queue;
+  THR_LOCK_DATA *lock_owner;
   DBUG_ENTER("thr_lock");
 
   data->next=0;
   data->cond=0;					/* safety */
   data->type=lock_type;
-  data->thread=pthread_self();			/* Must be reset ! */
-  data->thread_id=my_thread_id();		/* Must be reset ! */
+  data->owner= owner;                           /* Must be reset ! */
   VOID(pthread_mutex_lock(&lock->mutex));
   DBUG_PRINT("lock",("data: 0x%lx  thread: %ld  lock: 0x%lx  type: %d",
-		      data,data->thread_id,lock,(int) lock_type));
+		      data, data->owner->info->thread_id,
+                      lock, (int) lock_type));
   check_locks(lock,(uint) lock_type <= (uint) TL_READ_NO_INSERT ?
 	      "enter read_lock" : "enter write_lock",0);
   if ((int) lock_type <= (int) TL_READ_NO_INSERT)
@@ -454,8 +504,8 @@ int thr_lock(THR_LOCK_DATA *data,enum thr_lock_type lock_type)
       */
 
       DBUG_PRINT("lock",("write locked by thread: %ld",
-			 lock->write.data->thread_id));
-      if (pthread_equal(data->thread,lock->write.data->thread) ||
+			 lock->write.data->owner->info->thread_id));
+      if (thr_lock_owner_equal(data->owner, lock->write.data->owner) ||
 	  (lock->write.data->type <= TL_WRITE_DELAYED &&
 	   (((int) lock_type <= (int) TL_READ_HIGH_PRIORITY) ||
 	    (lock->write.data->type != TL_WRITE_CONCURRENT_INSERT &&
@@ -476,14 +526,14 @@ int thr_lock(THR_LOCK_DATA *data,enum thr_lock_type lock_type)
       {
 	/* We are not allowed to get a READ lock in this case */
 	data->type=TL_UNLOCK;
-	result=1;				/* Can't wait for this one */
+        result= THR_LOCK_ABORTED;               /* Can't wait for this one */
 	goto end;
       }
     }
     else if (!lock->write_wait.data ||
 	     lock->write_wait.data->type <= TL_WRITE_LOW_PRIORITY ||
 	     lock_type == TL_READ_HIGH_PRIORITY ||
-	     have_old_read_lock(lock->read.data,data->thread))
+	     have_old_read_lock(lock->read.data, data->owner))
     {						/* No important write-locks */
       (*lock->read.last)=data;			/* Add to running FIFO */
       data->prev=lock->read.last;
@@ -496,8 +546,12 @@ int thr_lock(THR_LOCK_DATA *data,enum thr_lock_type lock_type)
       statistic_increment(locks_immediate,&THR_LOCK_lock);
       goto end;
     }
-    /* Can't get lock yet;  Wait for it */
-    DBUG_RETURN(wait_for_lock(&lock->read_wait,data,0));
+    /*
+      We're here if there is an active write lock  or no write
+      lock but a high priority write waiting in the write_wait queue.
+      In the latter case we should yield the lock to the writer.
+    */
+    wait_queue= &lock->read_wait;
   }
   else						/* Request for WRITE lock */
   {
@@ -506,7 +560,7 @@ int thr_lock(THR_LOCK_DATA *data,enum thr_lock_type lock_type)
       if (lock->write.data && lock->write.data->type == TL_WRITE_ONLY)
       {
 	data->type=TL_UNLOCK;
-	result=1;				/* Can't wait for this one */
+        result= THR_LOCK_ABORTED;               /* Can't wait for this one */
 	goto end;
       }
       /*
@@ -540,7 +594,7 @@ int thr_lock(THR_LOCK_DATA *data,enum thr_lock_type lock_type)
       {
 	/* We are not allowed to get a lock in this case */
 	data->type=TL_UNLOCK;
-	result=1;				/* Can't wait for this one */
+        result= THR_LOCK_ABORTED;               /* Can't wait for this one */
 	goto end;
       }
 
@@ -549,7 +603,7 @@ int thr_lock(THR_LOCK_DATA *data,enum thr_lock_type lock_type)
 	TL_WRITE_ALLOW_WRITE, TL_WRITE_ALLOW_READ or TL_WRITE_DELAYED in
 	the same thread, but this will never happen within MySQL.
       */
-      if (pthread_equal(data->thread,lock->write.data->thread) ||
+      if (thr_lock_owner_equal(data->owner, lock->write.data->owner) ||
 	  (lock_type == TL_WRITE_ALLOW_WRITE &&
 	   !lock->write_wait.data &&
 	   lock->write.data->type == TL_WRITE_ALLOW_WRITE))
@@ -572,7 +626,7 @@ int thr_lock(THR_LOCK_DATA *data,enum thr_lock_type lock_type)
 	goto end;
       }
       DBUG_PRINT("lock",("write locked by thread: %ld",
-			 lock->write.data->thread_id));
+			 lock->write.data->owner->info->thread_id));
     }
     else
     {
@@ -608,10 +662,24 @@ int thr_lock(THR_LOCK_DATA *data,enum thr_lock_type lock_type)
 	}
       }
       DBUG_PRINT("lock",("write locked by thread: %ld, type: %ld",
-			 lock->read.data->thread_id,data->type));
+			 lock->read.data->owner->info->thread_id, data->type));
     }
-    DBUG_RETURN(wait_for_lock(&lock->write_wait,data,0));
+    wait_queue= &lock->write_wait;
   }
+  /*
+    Try to detect a trivial deadlock when using cursors: attempt to
+    lock a table that is already locked by an open cursor within the
+    same connection. lock_owner can be zero if we succumbed to a high
+    priority writer in the write_wait queue.
+  */
+  lock_owner= lock->read.data ? lock->read.data : lock->write.data;
+  if (lock_owner && lock_owner->owner->info == owner->info)
+  {
+    result= THR_LOCK_DEADLOCK;
+    goto end;
+  }
+  /* Can't get lock yet;  Wait for it */
+  DBUG_RETURN(wait_for_lock(wait_queue, data, 0));
 end:
   pthread_mutex_unlock(&lock->mutex);
   DBUG_RETURN(result);
@@ -656,7 +724,7 @@ static inline void free_all_read_locks(THR_LOCK *lock,
       lock->read_no_write_count++;
     }      
     DBUG_PRINT("lock",("giving read lock to thread: %ld",
-		       data->thread_id));
+		       data->owner->info->thread_id));
     data->cond=0;				/* Mark thread free */
     VOID(pthread_cond_signal(cond));
   } while ((data=data->next));
@@ -674,7 +742,7 @@ void thr_unlock(THR_LOCK_DATA *data)
   enum thr_lock_type lock_type=data->type;
   DBUG_ENTER("thr_unlock");
   DBUG_PRINT("lock",("data: 0x%lx  thread: %ld  lock: 0x%lx",
-		     data,data->thread_id,lock));
+		     data, data->owner->info->thread_id, lock));
   pthread_mutex_lock(&lock->mutex);
   check_locks(lock,"start of release lock",0);
 
@@ -734,7 +802,7 @@ void thr_unlock(THR_LOCK_DATA *data)
 	      (*lock->check_status)(data->status_param))
 	    data->type=TL_WRITE;			/* Upgrade lock */
 	  DBUG_PRINT("lock",("giving write lock of type %d to thread: %ld",
-			     data->type,data->thread_id));
+			     data->type, data->owner->info->thread_id));
 	  {
 	    pthread_cond_t *cond=data->cond;
 	    data->cond=0;				/* Mark thread free */
@@ -842,7 +910,8 @@ static void sort_locks(THR_LOCK_DATA **data,uint count)
 }
 
 
-int thr_multi_lock(THR_LOCK_DATA **data,uint count)
+enum enum_thr_lock_result
+thr_multi_lock(THR_LOCK_DATA **data, uint count, THR_LOCK_OWNER *owner)
 {
   THR_LOCK_DATA **pos,**end;
   DBUG_ENTER("thr_multi_lock");
@@ -852,10 +921,11 @@ int thr_multi_lock(THR_LOCK_DATA **data,uint count)
   /* lock everything */
   for (pos=data,end=data+count; pos < end ; pos++)
   {
-    if (thr_lock(*pos,(*pos)->type))
+    enum enum_thr_lock_result result= thr_lock(*pos, owner, (*pos)->type);
+    if (result != THR_LOCK_SUCCESS)
     {						/* Aborted */
       thr_multi_unlock(data,(uint) (pos-data));
-      DBUG_RETURN(1);
+      DBUG_RETURN(result);
     }
 #ifdef MAIN
     printf("Thread: %s  Got lock: 0x%lx  type: %d\n",my_thread_name(),
@@ -909,7 +979,7 @@ int thr_multi_lock(THR_LOCK_DATA **data,uint count)
     } while (pos != data);
   }
 #endif
-  DBUG_RETURN(0);
+  DBUG_RETURN(THR_LOCK_SUCCESS);
 }
 
   /* free all locks */
@@ -932,7 +1002,7 @@ void thr_multi_unlock(THR_LOCK_DATA **data,uint count)
     else
     {
       DBUG_PRINT("lock",("Free lock: data: 0x%lx  thread: %ld  lock: 0x%lx",
-			 *pos,(*pos)->thread_id,(*pos)->lock));
+			 *pos, (*pos)->owner->info->thread_id, (*pos)->lock));
     }
   }
   DBUG_VOID_RETURN;
@@ -952,6 +1022,7 @@ void thr_abort_locks(THR_LOCK *lock)
   for (data=lock->read_wait.data; data ; data=data->next)
   {
     data->type=TL_UNLOCK;			/* Mark killed */
+    /* It's safe to signal the cond first: we're still holding the mutex. */
     pthread_cond_signal(data->cond);
     data->cond=0;				/* Removed from list */
   }
@@ -985,10 +1056,11 @@ void thr_abort_locks_for_thread(THR_LOCK *lock, pthread_t thread)
   pthread_mutex_lock(&lock->mutex);
   for (data= lock->read_wait.data; data ; data= data->next)
   {
-    if (pthread_equal(thread, data->thread))
+    if (pthread_equal(thread, data->owner->info->thread))
     {
       DBUG_PRINT("info",("Aborting read-wait lock"));
       data->type= TL_UNLOCK;			/* Mark killed */
+      /* It's safe to signal the cond first: we're still holding the mutex. */
       pthread_cond_signal(data->cond);
       data->cond= 0;				/* Removed from list */
 
@@ -1000,7 +1072,7 @@ void thr_abort_locks_for_thread(THR_LOCK *lock, pthread_t thread)
   }
   for (data= lock->write_wait.data; data ; data= data->next)
   {
-    if (pthread_equal(thread, data->thread))
+    if (pthread_equal(thread, data->owner->info->thread))
     {
       DBUG_PRINT("info",("Aborting write-wait lock"));
       data->type= TL_UNLOCK;
@@ -1117,7 +1189,8 @@ static void thr_print_lock(const char* name,struct st_lock_list *list)
     prev= &list->data;
     for (data=list->data; data && count++ < MAX_LOCKS ; data=data->next)
     {
-      printf("0x%lx (%lu:%d); ",(ulong) data,data->thread_id,(int) data->type);
+      printf("0x%lx (%lu:%d); ", (ulong) data, data->owner->info->thread_id,
+             (int) data->type);
       if (data->prev != prev)
 	printf("\nWarning: prev didn't point at previous lock\n");
       prev= &data->next;
@@ -1250,11 +1323,16 @@ static void *test_thread(void *arg)
 {
   int i,j,param=*((int*) arg);
   THR_LOCK_DATA data[MAX_LOCK_COUNT];
+  THR_LOCK_OWNER owner;
+  THR_LOCK_INFO lock_info;
   THR_LOCK_DATA *multi_locks[MAX_LOCK_COUNT];
   my_thread_init();
 
   printf("Thread %s (%d) started\n",my_thread_name(),param); fflush(stdout);
 
+
+  thr_lock_info_init(&lock_info);
+  thr_lock_owner_init(&owner, &lock_info);
   for (i=0; i < lock_counts[param] ; i++)
     thr_lock_data_init(locks+tests[param][i].lock_nr,data+i,NULL);
   for (j=1 ; j < 10 ; j++)		/* try locking 10 times */
@@ -1264,7 +1342,7 @@ static void *test_thread(void *arg)
       multi_locks[i]= &data[i];
       data[i].type= tests[param][i].lock_type;
     }
-    thr_multi_lock(multi_locks,lock_counts[param]);
+    thr_multi_lock(multi_locks, lock_counts[param], &owner);
     pthread_mutex_lock(&LOCK_thread_count);
     {
       int tmp=rand() & 7;			/* Do something from 0-2 sec */
diff --git a/sql/examples/ha_archive.cc b/sql/examples/ha_archive.cc
index c362985f565..e5c35ae019d 100644
--- a/sql/examples/ha_archive.cc
+++ b/sql/examples/ha_archive.cc
@@ -149,7 +149,8 @@ static handlerton archive_hton = {
   0,       /* prepare */
   0,       /* recover */
   0,       /* commit_by_xid */
-  0        /* rollback_by_xid */
+  0,       /* rollback_by_xid */
+  HTON_NO_FLAGS
 };
 
 
@@ -208,6 +209,15 @@ bool archive_db_end()
   return FALSE;
 }
 
+ha_archive::ha_archive(TABLE *table_arg)
+  :handler(&archive_hton, table_arg), delayed_insert(0), bulk_insert(0)
+{
+  /* Set our original buffer from pre-allocated memory */
+  buffer.set((char *)byte_buffer, IO_SIZE, system_charset_info);
+
+  /* The size of the offset value we will use for position() */
+  ref_length = sizeof(z_off_t);
+}
 
 /*
   This method reads the header of a datafile and returns whether or not it was successful.
diff --git a/sql/examples/ha_archive.h b/sql/examples/ha_archive.h
index 3932b62980c..41835c5fb6f 100644
--- a/sql/examples/ha_archive.h
+++ b/sql/examples/ha_archive.h
@@ -58,14 +58,7 @@ class ha_archive: public handler
   bool bulk_insert;          /* If we are performing a bulk insert */
 
 public:
-  ha_archive(TABLE *table): handler(table), delayed_insert(0), bulk_insert(0)
-  {
-    /* Set our original buffer from pre-allocated memory */
-    buffer.set((char *)byte_buffer, IO_SIZE, system_charset_info);
-
-    /* The size of the offset value we will use for position() */
-    ref_length = sizeof(z_off_t);
-  }
+  ha_archive(TABLE *table_arg);
   ~ha_archive()
   {
   }
diff --git a/sql/examples/ha_example.cc b/sql/examples/ha_example.cc
index 9da297ccd1f..2818c176cd3 100644
--- a/sql/examples/ha_example.cc
+++ b/sql/examples/ha_example.cc
@@ -72,6 +72,24 @@
 #ifdef HAVE_EXAMPLE_DB
 #include "ha_example.h"
 
+
+static handlerton example_hton= {
+  "CSV",
+  0,       /* slot */
+  0,       /* savepoint size. */
+  0,       /* close_connection */
+  0,       /* savepoint */
+  0,       /* rollback to savepoint */
+  0,       /* release savepoint */
+  0,       /* commit */
+  0,       /* rollback */
+  0,       /* prepare */
+  0,       /* recover */
+  0,       /* commit_by_xid */
+  0,       /* rollback_by_xid */
+  HTON_NO_FLAGS
+};
+
 /* Variables for example share methods */
 static HASH example_open_tables; // Hash used to track open tables
 pthread_mutex_t example_mutex;   // This is the mutex we use to init the hash
@@ -179,6 +197,10 @@ static int free_share(EXAMPLE_SHARE *share)
 }
 
 
+ha_example::ha_example(TABLE *table_arg)
+  :handler(&example_hton, table_arg)
+{}
+
 /*
   If frm_error() is called then we will use this to to find out what file extentions
   exist for the storage engine. This is also used by the default rename_table and
diff --git a/sql/examples/ha_example.h b/sql/examples/ha_example.h
index ae72e5bb275..37f38fe5210 100644
--- a/sql/examples/ha_example.h
+++ b/sql/examples/ha_example.h
@@ -45,9 +45,7 @@ class ha_example: public handler
   EXAMPLE_SHARE *share;    /* Shared lock info */
 
 public:
-  ha_example(TABLE *table): handler(table)
-  {
-  }
+  ha_example(TABLE *table_arg);
   ~ha_example()
   {
   }
diff --git a/sql/examples/ha_tina.cc b/sql/examples/ha_tina.cc
index a030960d08a..9c774c1f75c 100644
--- a/sql/examples/ha_tina.cc
+++ b/sql/examples/ha_tina.cc
@@ -54,6 +54,23 @@ pthread_mutex_t tina_mutex;
 static HASH tina_open_tables;
 static int tina_init= 0;
 
+static handlerton tina_hton= {
+  "CSV",
+  0,       /* slot */
+  0,       /* savepoint size. */
+  0,       /* close_connection */
+  0,       /* savepoint */
+  0,       /* rollback to savepoint */
+  0,       /* release savepoint */
+  0,       /* commit */
+  0,       /* rollback */
+  0,       /* prepare */
+  0,       /* recover */
+  0,       /* commit_by_xid */
+  0,       /* rollback_by_xid */
+  HTON_NO_FLAGS
+};
+
 /*****************************************************************************
  ** TINA tables
  *****************************************************************************/
@@ -228,6 +245,20 @@ byte * find_eoln(byte *data, off_t begin, off_t end)
   return 0;
 }
 
+
+ha_tina::ha_tina(TABLE *table_arg)
+  :handler(&tina_hton, table_arg),
+  /*
+    These definitions are found in hanler.h
+    These are not probably completely right.
+  */
+  current_position(0), next_position(0), chain_alloced(0), chain_size(DEFAULT_CHAIN_LENGTH)
+{
+  /* Set our original buffers from pre-allocated memory */
+  buffer.set(byte_buffer, IO_SIZE, system_charset_info);
+  chain= chain_buffer;
+}
+
 /*
   Encode a buffer into the quoted format.
 */
diff --git a/sql/examples/ha_tina.h b/sql/examples/ha_tina.h
index 22193c01013..5679d77a4dc 100644
--- a/sql/examples/ha_tina.h
+++ b/sql/examples/ha_tina.h
@@ -49,18 +49,8 @@ class ha_tina: public handler
   byte chain_alloced;
   uint32 chain_size;
 
-  public:
-  ha_tina(TABLE *table): handler(table),
-  /* 
-     These definitions are found in hanler.h 
-     Theses are not probably completely right.
-   */
-  current_position(0), next_position(0), chain_alloced(0), chain_size(DEFAULT_CHAIN_LENGTH)
-  {
-    /* Set our original buffers from pre-allocated memory */
-    buffer.set(byte_buffer, IO_SIZE, system_charset_info);
-    chain = chain_buffer;
-  }
+public:
+  ha_tina(TABLE *table_arg);
   ~ha_tina() 
   {
     if (chain_alloced)
diff --git a/sql/ha_berkeley.cc b/sql/ha_berkeley.cc
index 568fb727e63..26e743d4a71 100644
--- a/sql/ha_berkeley.cc
+++ b/sql/ha_berkeley.cc
@@ -120,7 +120,8 @@ static handlerton berkeley_hton = {
   NULL, /* prepare */
   NULL, /* recover */
   NULL, /* commit_by_xid */
-  NULL /* rollback_by_xid */
+  NULL, /* rollback_by_xid */
+  HTON_CLOSE_CURSORS_AT_COMMIT
 };
 
 typedef struct st_berkeley_trx_data {
@@ -372,6 +373,17 @@ void berkeley_cleanup_log_files(void)
 /*****************************************************************************
 ** Berkeley DB tables
 *****************************************************************************/
+
+ha_berkeley::ha_berkeley(TABLE *table_arg)
+  :handler(&berkeley_hton, table_arg), alloc_ptr(0), rec_buff(0), file(0),
+  int_table_flags(HA_REC_NOT_IN_SEQ | HA_FAST_KEY_READ |
+                  HA_NULL_IN_KEY | HA_CAN_INDEX_BLOBS | HA_NOT_EXACT_COUNT |
+                  HA_PRIMARY_KEY_IN_READ_INDEX | HA_FILE_BASED |
+                  HA_AUTO_PART_KEY | HA_TABLE_SCAN_ON_INDEX),
+  changed_rows(0), last_dup_key((uint) -1), version(0), using_ignore(0)
+{}
+
+
 static const char *ha_berkeley_exts[] = {
   ha_berkeley_ext,
   NullS
diff --git a/sql/ha_berkeley.h b/sql/ha_berkeley.h
index f6376939445..aa92908ecde 100644
--- a/sql/ha_berkeley.h
+++ b/sql/ha_berkeley.h
@@ -85,12 +85,7 @@ class ha_berkeley: public handler
   DBT *get_pos(DBT *to, byte *pos);
 
  public:
-  ha_berkeley(TABLE *table): handler(table), alloc_ptr(0),rec_buff(0), file(0),
-    int_table_flags(HA_REC_NOT_IN_SEQ | HA_FAST_KEY_READ |
-		    HA_NULL_IN_KEY | HA_CAN_INDEX_BLOBS | HA_NOT_EXACT_COUNT |
-		    HA_PRIMARY_KEY_IN_READ_INDEX | HA_FILE_BASED |
-		    HA_AUTO_PART_KEY | HA_TABLE_SCAN_ON_INDEX),
-    changed_rows(0),last_dup_key((uint) -1),version(0),using_ignore(0) {}
+  ha_berkeley(TABLE *table_arg);
   ~ha_berkeley() {}
   const char *table_type() const { return "BerkeleyDB"; }
   ulong index_flags(uint idx, uint part, bool all_parts) const;
diff --git a/sql/ha_blackhole.cc b/sql/ha_blackhole.cc
index 6abbe983f48..856a053db9e 100644
--- a/sql/ha_blackhole.cc
+++ b/sql/ha_blackhole.cc
@@ -24,6 +24,34 @@
 #include "ha_blackhole.h"
 
 
+/* Blackhole storage engine handlerton */
+
+static handlerton myisam_hton= {
+  "BLACKHOLE",
+  0,       /* slot */
+  0,       /* savepoint size. */
+  0,       /* close_connection */
+  0,       /* savepoint */
+  0,       /* rollback to savepoint */
+  0,       /* release savepoint */
+  0,       /* commit */
+  0,       /* rollback */
+  0,       /* prepare */
+  0,       /* recover */
+  0,       /* commit_by_xid */
+  0,       /* rollback_by_xid */
+  HTON_NO_FLAGS
+};
+
+/*****************************************************************************
+** BLACKHOLE tables
+*****************************************************************************/
+
+ha_blackhole::ha_blackhole(TABLE *table_arg)
+  :handler(&blackhole_hton, table_arg)
+{}
+
+
 static const char *ha_blackhole_exts[] = {
   NullS
 };
diff --git a/sql/ha_blackhole.h b/sql/ha_blackhole.h
index 84a386e17f8..2dccabf17cc 100644
--- a/sql/ha_blackhole.h
+++ b/sql/ha_blackhole.h
@@ -28,9 +28,7 @@ class ha_blackhole: public handler
   THR_LOCK thr_lock;
 
 public:
-  ha_blackhole(TABLE *table): handler(table)
-  {
-  }
+  ha_blackhole(TABLE *table_arg);
   ~ha_blackhole()
   {
   }
diff --git a/sql/ha_federated.cc b/sql/ha_federated.cc
index e0e35c6b866..1d7b8cda8e2 100644
--- a/sql/ha_federated.cc
+++ b/sql/ha_federated.cc
@@ -679,6 +679,37 @@ error:
 }
 
 
+/* Federated storage engine handlerton */
+
+static handlerton federated_hton= {
+  "FEDERATED",
+  0,       /* slot */
+  0,       /* savepoint size. */
+  0,       /* close_connection */
+  0,       /* savepoint */
+  0,       /* rollback to savepoint */
+  0,       /* release savepoint */
+  0,       /* commit */
+  0,       /* rollback */
+  0,       /* prepare */
+  0,       /* recover */
+  0,       /* commit_by_xid */
+  0,       /* rollback_by_xid */
+  HTON_NO_FLAGS
+};
+
+
+/*****************************************************************************
+** FEDERATED tables
+*****************************************************************************/
+
+ha_federated::ha_federated(TABLE *table_arg)
+  :handler(&federated_hton, table_arg),
+  mysql(0), stored_result(0), scan_flag(0),
+  ref_length(sizeof(MYSQL_ROW_OFFSET)), current_position(0)
+{}
+
+
 /*
   Convert MySQL result set row to handler internal format
 
diff --git a/sql/ha_federated.h b/sql/ha_federated.h
index 3e55419f266..58b78ab0dde 100644
--- a/sql/ha_federated.h
+++ b/sql/ha_federated.h
@@ -162,11 +162,7 @@ private:
                              bool records_in_range);
 
 public:
-  ha_federated(TABLE *table): handler(table),
-    mysql(0), stored_result(0), scan_flag(0),
-    ref_length(sizeof(MYSQL_ROW_OFFSET)), current_position(0)
-  {
-  }
+  ha_federated(TABLE *table_arg);
   ~ha_federated()
   {
   }
diff --git a/sql/ha_heap.cc b/sql/ha_heap.cc
index 6e609a94be3..92a5fe0ea09 100644
--- a/sql/ha_heap.cc
+++ b/sql/ha_heap.cc
@@ -23,9 +23,33 @@
 #include <myisampack.h>
 #include "ha_heap.h"
 
+static handlerton heap_hton= {
+  "MEMORY",
+  0,       /* slot */
+  0,       /* savepoint size. */
+  0,       /* close_connection */
+  0,       /* savepoint */
+  0,       /* rollback to savepoint */
+  0,       /* release savepoint */
+  0,       /* commit */
+  0,       /* rollback */
+  0,       /* prepare */
+  0,       /* recover */
+  0,       /* commit_by_xid */
+  0,       /* rollback_by_xid */
+  HTON_NO_FLAGS
+};
+
 /*****************************************************************************
 ** HEAP tables
 *****************************************************************************/
+
+ha_heap::ha_heap(TABLE *table_arg)
+  :handler(&heap_hton, table_arg), file(0), records_changed(0),
+  key_stats_ok(0)
+{}
+
+
 static const char *ha_heap_exts[] = {
   NullS
 };
diff --git a/sql/ha_heap.h b/sql/ha_heap.h
index 7a97c727049..f7368436456 100644
--- a/sql/ha_heap.h
+++ b/sql/ha_heap.h
@@ -31,8 +31,7 @@ class ha_heap: public handler
   uint    records_changed;
   bool    key_stats_ok;
 public:
-  ha_heap(TABLE *table): handler(table), file(0), records_changed(0),
-      key_stats_ok(0) {}
+  ha_heap(TABLE *table);
   ~ha_heap() {}
   const char *table_type() const
   {
diff --git a/sql/ha_innodb.cc b/sql/ha_innodb.cc
index 98199a22efe..69451493d4b 100644
--- a/sql/ha_innodb.cc
+++ b/sql/ha_innodb.cc
@@ -215,7 +215,14 @@ static handlerton innobase_hton = {
   innobase_xa_prepare,		/* prepare */
   innobase_xa_recover,		/* recover */
   innobase_commit_by_xid,	/* commit_by_xid */
-  innobase_rollback_by_xid	/* rollback_by_xid */
+  innobase_rollback_by_xid,     /* rollback_by_xid */
+  /*
+    For now when one opens a cursor, MySQL does not create an own
+    InnoDB consistent read view for it, and uses the view of the
+    currently active transaction. Therefore, cursors can not
+    survive COMMIT or ROLLBACK statements, which free this view.
+  */
+  HTON_CLOSE_CURSORS_AT_COMMIT
 };
 
 /*********************************************************************
@@ -765,6 +772,24 @@ check_trx_exists(
 	return(trx);
 }
 
+
+/*************************************************************************
+Construct ha_innobase handler. */
+
+ha_innobase::ha_innobase(TABLE *table_arg)
+  :handler(&innobase_hton, table_arg),
+  int_table_flags(HA_REC_NOT_IN_SEQ |
+                  HA_NULL_IN_KEY |
+                  HA_CAN_INDEX_BLOBS |
+                  HA_CAN_SQL_HANDLER |
+                  HA_NOT_EXACT_COUNT |
+                  HA_PRIMARY_KEY_IN_READ_INDEX |
+                  HA_TABLE_SCAN_ON_INDEX),
+  last_dup_key((uint) -1),
+  start_of_scan(0),
+  num_write_row(0)
+{}
+
 /*************************************************************************
 Updates the user_thd field in a handle and also allocates a new InnoDB
 transaction handle if needed, and updates the transaction fields in the
diff --git a/sql/ha_innodb.h b/sql/ha_innodb.h
index 90cae3998ed..1584a2182c9 100644
--- a/sql/ha_innodb.h
+++ b/sql/ha_innodb.h
@@ -81,19 +81,7 @@ class ha_innobase: public handler
 
 	/* Init values for the class: */
  public:
-  	ha_innobase(TABLE *table): handler(table),
-	  int_table_flags(HA_REC_NOT_IN_SEQ |
-			  HA_NULL_IN_KEY |
-			  HA_CAN_INDEX_BLOBS |
-			  HA_CAN_SQL_HANDLER |
-			  HA_NOT_EXACT_COUNT |
-			  HA_PRIMARY_KEY_IN_READ_INDEX |
-			  HA_TABLE_SCAN_ON_INDEX),
-	  last_dup_key((uint) -1),
-	  start_of_scan(0),
-	  num_write_row(0)
-  	{
-  	}
+  	ha_innobase(TABLE *table_arg);
   	~ha_innobase() {}
 	/*
 	  Get the row type from the storage engine.  If this method returns
diff --git a/sql/ha_myisam.cc b/sql/ha_myisam.cc
index e94b697e0bb..fefa05e92b0 100644
--- a/sql/ha_myisam.cc
+++ b/sql/ha_myisam.cc
@@ -44,6 +44,29 @@ TYPELIB myisam_recover_typelib= {array_elements(myisam_recover_names)-1,"",
 ** MyISAM tables
 *****************************************************************************/
 
+/* MyISAM handlerton */
+
+static handlerton myisam_hton= {
+  "MyISAM",
+  0,       /* slot */
+  0,       /* savepoint size. */
+  0,       /* close_connection */
+  0,       /* savepoint */
+  0,       /* rollback to savepoint */
+  0,       /* release savepoint */
+  0,       /* commit */
+  0,       /* rollback */
+  0,       /* prepare */
+  0,       /* recover */
+  0,       /* commit_by_xid */
+  0,       /* rollback_by_xid */
+  /*
+    MyISAM doesn't support transactions and doesn't have
+    transaction-dependent context: cursors can survive a commit.
+  */
+  HTON_NO_FLAGS
+};
+
 // collect errors printed by mi_check routines
 
 static void mi_check_print_msg(MI_CHECK *param,	const char* msg_type,
@@ -123,6 +146,17 @@ void mi_check_print_warning(MI_CHECK *param, const char *fmt,...)
 
 }
 
+
+ha_myisam::ha_myisam(TABLE *table_arg)
+  :handler(&myisam_hton, table_arg), file(0),
+  int_table_flags(HA_NULL_IN_KEY | HA_CAN_FULLTEXT | HA_CAN_SQL_HANDLER |
+                  HA_DUPP_POS | HA_CAN_INDEX_BLOBS | HA_AUTO_PART_KEY |
+                  HA_FILE_BASED | HA_CAN_GEOMETRY | HA_READ_RND_SAME |
+                  HA_CAN_INSERT_DELAYED | HA_CAN_BIT_FIELD),
+  can_enable_indexes(1)
+{}
+
+
 static const char *ha_myisam_exts[] = {
   ".MYI",
   ".MYD",
diff --git a/sql/ha_myisam.h b/sql/ha_myisam.h
index bbd9721f8e2..ca684463311 100644
--- a/sql/ha_myisam.h
+++ b/sql/ha_myisam.h
@@ -43,13 +43,7 @@ class ha_myisam: public handler
   int repair(THD *thd, MI_CHECK &param, bool optimize);
 
  public:
-  ha_myisam(TABLE *table): handler(table), file(0),
-    int_table_flags(HA_NULL_IN_KEY | HA_CAN_FULLTEXT | HA_CAN_SQL_HANDLER |
-		    HA_DUPP_POS | HA_CAN_INDEX_BLOBS | HA_AUTO_PART_KEY |
-		    HA_FILE_BASED | HA_CAN_GEOMETRY | HA_READ_RND_SAME |
-                    HA_CAN_INSERT_DELAYED | HA_CAN_BIT_FIELD),
-    can_enable_indexes(1)
-  {}
+  ha_myisam(TABLE *table_arg);
   ~ha_myisam() {}
   const char *table_type() const { return "MyISAM"; }
   const char *index_type(uint key_number);
diff --git a/sql/ha_myisammrg.cc b/sql/ha_myisammrg.cc
index 5d3f379081c..8c4b4e790b1 100644
--- a/sql/ha_myisammrg.cc
+++ b/sql/ha_myisammrg.cc
@@ -32,6 +32,30 @@
 ** MyISAM MERGE tables
 *****************************************************************************/
 
+/* MyISAM MERGE handlerton */
+
+static handlerton myisammrg_hton= {
+  "MRG_MyISAM",
+  0,       /* slot */
+  0,       /* savepoint size. */
+  0,       /* close_connection */
+  0,       /* savepoint */
+  0,       /* rollback to savepoint */
+  0,       /* release savepoint */
+  0,       /* commit */
+  0,       /* rollback */
+  0,       /* prepare */
+  0,       /* recover */
+  0,       /* commit_by_xid */
+  0,       /* rollback_by_xid */
+  HTON_NO_FLAGS
+};
+
+
+ha_myisammrg::ha_myisammrg(TABLE *table_arg)
+  :handler(&myisammrg_hton, table_arg), file(0)
+{}
+
 static const char *ha_myisammrg_exts[] = {
   ".MRG",
   NullS
diff --git a/sql/ha_myisammrg.h b/sql/ha_myisammrg.h
index 7348096b695..c762b7c286e 100644
--- a/sql/ha_myisammrg.h
+++ b/sql/ha_myisammrg.h
@@ -28,7 +28,7 @@ class ha_myisammrg: public handler
   MYRG_INFO *file;
 
  public:
-  ha_myisammrg(TABLE *table): handler(table), file(0) {}
+  ha_myisammrg(TABLE *table_arg);
   ~ha_myisammrg() {}
   const char *table_type() const { return "MRG_MyISAM"; }
   const char **bas_ext() const;
diff --git a/sql/ha_ndbcluster.cc b/sql/ha_ndbcluster.cc
index d35b8af80aa..81723690b83 100644
--- a/sql/ha_ndbcluster.cc
+++ b/sql/ha_ndbcluster.cc
@@ -62,7 +62,8 @@ static handlerton ndbcluster_hton = {
   NULL, /* prepare */
   NULL, /* recover */
   NULL, /* commit_by_xid */
-  NULL  /* rollback_by_xid */
+  NULL, /* rollback_by_xid */
+  HTON_NO_FLAGS
 };
 
 #define NDB_HIDDEN_PRIMARY_KEY_LENGTH 8
@@ -4174,7 +4175,7 @@ ulonglong ha_ndbcluster::get_auto_increment()
  */
 
 ha_ndbcluster::ha_ndbcluster(TABLE *table_arg):
-  handler(table_arg),
+  handler(&ndbcluster_hton, table_arg),
   m_active_trans(NULL),
   m_active_cursor(NULL),
   m_table(NULL),
diff --git a/sql/handler.cc b/sql/handler.cc
index a61dce35501..cf5ddd95764 100644
--- a/sql/handler.cc
+++ b/sql/handler.cc
@@ -208,15 +208,8 @@ handler *get_new_handler(TABLE *table, enum db_type db_type)
   case DB_TYPE_HASH:
     return new ha_hash(table);
 #endif
-#ifdef HAVE_ISAM
-  case DB_TYPE_MRG_ISAM:
-    return new ha_isammrg(table);
-  case DB_TYPE_ISAM:
-    return new ha_isam(table);
-#else
   case DB_TYPE_MRG_ISAM:
     return new ha_myisammrg(table);
-#endif
 #ifdef HAVE_BERKELEY_DB
   case DB_TYPE_BERKELEY_DB:
     return new ha_berkeley(table);
@@ -634,6 +627,11 @@ int ha_commit_trans(THD *thd, bool all)
       DBUG_RETURN(1);
     }
     DBUG_EXECUTE_IF("crash_commit_before", abort(););
+
+    /* Close all cursors that can not survive COMMIT */
+    if (is_real_trans)                          /* not a statement commit */
+      thd->stmt_map.close_transient_cursors();
+
     if (!trans->no_2pc && trans->nht > 1)
     {
       for (; *ht && !error; ht++)
@@ -735,6 +733,10 @@ int ha_rollback_trans(THD *thd, bool all)
 #ifdef USING_TRANSACTIONS
   if (trans->nht)
   {
+    /* Close all cursors that can not survive ROLLBACK */
+    if (is_real_trans)                          /* not a statement commit */
+      thd->stmt_map.close_transient_cursors();
+
     for (handlerton **ht=trans->ht; *ht; ht++)
     {
       int err;
diff --git a/sql/handler.h b/sql/handler.h
index df906e284e7..02b2353b890 100644
--- a/sql/handler.h
+++ b/sql/handler.h
@@ -349,8 +349,13 @@ typedef struct
    int  (*recover)(XID *xid_list, uint len);
    int  (*commit_by_xid)(XID *xid);
    int  (*rollback_by_xid)(XID *xid);
+   uint32 flags;                                /* global handler flags */
 } handlerton;
 
+/* Possible flags of a handlerton */
+#define HTON_NO_FLAGS 0
+#define HTON_CLOSE_CURSORS_AT_COMMIT 1
+
 typedef struct st_thd_trans
 {
   /* number of entries in the ht[] */
@@ -445,6 +450,7 @@ class handler :public Sql_alloc
   virtual int rnd_end() { return 0; }
 
 public:
+  const handlerton *ht;                 /* storage engine of this handler */
   byte *ref;				/* Pointer to current row */
   byte *dupp_ref;			/* Pointer to dupp row */
   ulonglong data_file_length;		/* Length off data file */
@@ -486,7 +492,8 @@ public:
   bool implicit_emptied;                /* Can be !=0 only if HEAP */
   const COND *pushed_cond;
 
-  handler(TABLE *table_arg) :table(table_arg),
+  handler(const handlerton *ht_arg, TABLE *table_arg) :table(table_arg),
+    ht(ht_arg),
     ref(0), data_file_length(0), max_data_file_length(0), index_file_length(0),
     delete_length(0), auto_increment_value(0),
     records(0), deleted(0), mean_rec_length(0),
diff --git a/sql/lock.cc b/sql/lock.cc
index 7f3fe5ac5da..aa162a23b40 100644
--- a/sql/lock.cc
+++ b/sql/lock.cc
@@ -103,6 +103,10 @@ MYSQL_LOCK *mysql_lock_tables(THD *thd, TABLE **tables, uint count, uint flags)
 {
   MYSQL_LOCK *sql_lock;
   TABLE *write_lock_used;
+  int rc;
+  /* Map the return value of thr_lock to an error from errmsg.txt */
+  const static int thr_lock_errno_to_mysql[]=
+  { 0, 1, ER_LOCK_WAIT_TIMEOUT, ER_LOCK_DEADLOCK };
   DBUG_ENTER("mysql_lock_tables");
 
   for (;;)
@@ -135,15 +139,24 @@ MYSQL_LOCK *mysql_lock_tables(THD *thd, TABLE **tables, uint count, uint flags)
     {
       my_free((gptr) sql_lock,MYF(0));
       sql_lock=0;
-      thd->proc_info=0;
       break;
     }
     thd->proc_info="Table lock";
     thd->locked=1;
-    if (thr_multi_lock(sql_lock->locks,sql_lock->lock_count))
+    rc= thr_lock_errno_to_mysql[(int) thr_multi_lock(sql_lock->locks,
+                                                     sql_lock->lock_count,
+                                                     thd->lock_id)];
+    if (rc > 1)                                 /* a timeout or a deadlock */
+    {
+      my_error(rc, MYF(0));
+      my_free((gptr) sql_lock,MYF(0));
+      sql_lock= 0;
+      break;
+    }
+    else if (rc == 1)                           /* aborted */
     {
       thd->some_tables_deleted=1;		// Try again
-      sql_lock->lock_count=0;			// Locks are alread freed
+      sql_lock->lock_count= 0;                  // Locks are already freed
     }
     else if (!thd->some_tables_deleted || (flags & MYSQL_LOCK_IGNORE_FLUSH))
     {
diff --git a/sql/mysqld.cc b/sql/mysqld.cc
index 7c8b2b781e4..f31a6727619 100644
--- a/sql/mysqld.cc
+++ b/sql/mysqld.cc
@@ -4342,7 +4342,8 @@ enum options_mysqld
   OPT_ENABLE_LARGE_PAGES,
   OPT_TIMED_MUTEXES,
   OPT_OLD_STYLE_USER_LIMITS,
-  OPT_LOG_SLOW_ADMIN_STATEMENTS
+  OPT_LOG_SLOW_ADMIN_STATEMENTS,
+  OPT_TABLE_LOCK_WAIT_TIMEOUT
 };
 
 
@@ -5595,6 +5596,11 @@ The minimum value for this variable is 4096.",
    "The number of open tables for all threads.", (gptr*) &table_cache_size,
    (gptr*) &table_cache_size, 0, GET_ULONG, REQUIRED_ARG, 64, 1, 512*1024L,
    0, 1, 0},
+  {"table_lock_wait_timeout", OPT_TABLE_LOCK_WAIT_TIMEOUT, "Timeout in "
+    "seconds to wait for a table level lock before returning an error. Used"
+     " only if the connection has active cursors.",
+   (gptr*) &table_lock_wait_timeout, (gptr*) &table_lock_wait_timeout,
+   0, GET_ULONG, REQUIRED_ARG, 50, 1, 1024 * 1024 * 1024, 0, 1, 0},
   {"thread_cache_size", OPT_THREAD_CACHE_SIZE,
    "How many threads we should keep in a cache for reuse.",
    (gptr*) &thread_cache_size, (gptr*) &thread_cache_size, 0, GET_ULONG,
@@ -7083,4 +7089,6 @@ template class I_List_iterator<THD>;
 template class I_List<i_string>;
 template class I_List<i_string_pair>;
 template class I_List<NAMED_LIST>;
+template class I_List<Statement>;
+template class I_List_iterator<Statement>;
 #endif
diff --git a/sql/set_var.cc b/sql/set_var.cc
index 2d7c3364e41..09581aed217 100644
--- a/sql/set_var.cc
+++ b/sql/set_var.cc
@@ -375,6 +375,8 @@ sys_var_thd_ulong	sys_sync_replication_timeout(
 sys_var_bool_ptr	sys_sync_frm("sync_frm", &opt_sync_frm);
 sys_var_long_ptr	sys_table_cache_size("table_cache",
 					     &table_cache_size);
+sys_var_long_ptr	sys_table_lock_wait_timeout("table_lock_wait_timeout",
+                                                    &table_lock_wait_timeout);
 sys_var_long_ptr	sys_thread_cache_size("thread_cache_size",
 					      &thread_cache_size);
 sys_var_thd_enum	sys_tx_isolation("tx_isolation",
@@ -682,6 +684,7 @@ sys_var *sys_variables[]=
 #endif
   &sys_sync_frm,
   &sys_table_cache_size,
+  &sys_table_lock_wait_timeout,
   &sys_table_type,
   &sys_thread_cache_size,
   &sys_time_format,
@@ -972,6 +975,7 @@ struct show_var_st init_vars[]= {
   {"system_time_zone",        system_time_zone,                     SHOW_CHAR},
 #endif
   {"table_cache",             (char*) &table_cache_size,            SHOW_LONG},
+  {"table_lock_wait_timeout", (char*) &table_lock_wait_timeout,     SHOW_LONG },
   {sys_table_type.name,	      (char*) &sys_table_type,	            SHOW_SYS},
   {sys_thread_cache_size.name,(char*) &sys_thread_cache_size,       SHOW_SYS},
 #ifdef HAVE_THR_SETCONCURRENCY
diff --git a/sql/sql_class.cc b/sql/sql_class.cc
index d0ac1a16f6b..89d5b543dfc 100644
--- a/sql/sql_class.cc
+++ b/sql/sql_class.cc
@@ -173,6 +173,7 @@ Open_tables_state::Open_tables_state()
 THD::THD()
   :Statement(CONVENTIONAL_EXECUTION, 0, ALLOC_ROOT_MIN_BLOCK_SIZE, 0),
    Open_tables_state(),
+   lock_id(&main_lock_id),
    user_time(0), global_read_lock(0), is_fatal_error(0),
    rand_used(0), time_zone_used(0),
    last_insert_id_used(0), insert_id_used(0), clear_next_insert_id(0),
@@ -265,6 +266,8 @@ THD::THD()
   tablespace_op=FALSE;
   ulong tmp=sql_rnd_with_mutex();
   randominit(&rand, tmp + (ulong) &rand, tmp + (ulong) ::query_id);
+  thr_lock_info_init(&lock_info); /* safety: will be reset after start */
+  thr_lock_owner_init(&main_lock_id, &lock_info);
 }
 
 
@@ -406,6 +409,8 @@ THD::~THD()
     net_end(&net);
   }
 #endif
+  stmt_map.destroy();                     /* close all prepared statements */
+  DBUG_ASSERT(lock_info.n_cursors == 0);
   if (!cleanup_done)
     cleanup();
 
@@ -518,6 +523,7 @@ bool THD::store_globals()
     if this is the slave SQL thread.
   */
   variables.pseudo_thread_id= thread_id;
+  thr_lock_info_init(&lock_info);
   return 0;
 }
 
@@ -1563,6 +1569,12 @@ void Statement::restore_backup_statement(Statement *stmt, Statement *backup)
 }
 
 
+void Statement::close_cursor()
+{
+  DBUG_ASSERT("Statement::close_cursor()" == "not implemented");
+}
+
+
 void THD::end_statement()
 {
   /* Cleanup SQL processing state to resuse this statement in next query. */
@@ -1683,6 +1695,14 @@ int Statement_map::insert(Statement *statement)
 }
 
 
+void Statement_map::close_transient_cursors()
+{
+  Statement *stmt;
+  while ((stmt= transient_cursor_list.head()))
+    stmt->close_cursor();                 /* deletes itself from the list */
+}
+
+
 bool select_dumpvar::send_data(List<Item> &items)
 {
   List_iterator_fast<Item_func_set_user_var> li(vars);
diff --git a/sql/sql_class.h b/sql/sql_class.h
index 6c4315b95fa..d6847f5fb35 100644
--- a/sql/sql_class.h
+++ b/sql/sql_class.h
@@ -756,7 +756,7 @@ class Cursor;
   be used explicitly.
 */
 
-class Statement: public Query_arena
+class Statement: public ilink, public Query_arena
 {
   Statement(const Statement &rhs);              /* not implemented: */
   Statement &operator=(const Statement &rhs);   /* non-copyable */
@@ -833,6 +833,8 @@ public:
   void restore_backup_statement(Statement *stmt, Statement *backup);
   /* return class type */
   virtual Type type() const;
+  /* Close the cursor open for this statement, if there is one */
+  virtual void close_cursor();
 };
 
 
@@ -884,15 +886,25 @@ public:
     }
     hash_delete(&st_hash, (byte *) statement);
   }
+  void add_transient_cursor(Statement *stmt)
+  { transient_cursor_list.append(stmt); }
+  void erase_transient_cursor(Statement *stmt) { stmt->unlink(); }
+  /*
+    Close all cursors of this connection that use tables of a storage
+    engine that has transaction-specific state and therefore can not
+    survive COMMIT or ROLLBACK. Currently all but MyISAM cursors are closed.
+  */
+  void close_transient_cursors();
   /* Erase all statements (calls Statement destructor) */
   void reset()
   {
     my_hash_reset(&names_hash);
     my_hash_reset(&st_hash);
+    transient_cursor_list.empty();
     last_found_statement= 0;
   }
 
-  ~Statement_map()
+  void destroy()
   {
     hash_free(&names_hash);
     hash_free(&st_hash);
@@ -900,6 +912,7 @@ public:
 private:
   HASH st_hash;
   HASH names_hash;
+  I_List<Statement> transient_cursor_list;
   Statement *last_found_statement;
 };
 
@@ -1017,8 +1030,7 @@ public:
   a thread/connection descriptor
 */
 
-class THD :public ilink,
-           public Statement,
+class THD :public Statement,
            public Open_tables_state
 {
 public:
@@ -1044,6 +1056,10 @@ public:
   struct  rand_struct rand;		// used for authentication
   struct  system_variables variables;	// Changeable local variables
   struct  system_status_var status_var; // Per thread statistic vars
+  THR_LOCK_INFO lock_info;              // Locking info of this thread
+  THR_LOCK_OWNER main_lock_id;          // To use for conventional queries
+  THR_LOCK_OWNER *lock_id;              // If not main_lock_id, points to
+                                        // the lock_id of a cursor.
   pthread_mutex_t LOCK_delete;		// Locked before thd is deleted
   /* all prepared statements and cursors of this connection */
   Statement_map stmt_map; 
diff --git a/sql/sql_prepare.cc b/sql/sql_prepare.cc
index aa47b506f73..b0f93463a8e 100644
--- a/sql/sql_prepare.cc
+++ b/sql/sql_prepare.cc
@@ -2020,6 +2020,7 @@ void mysql_stmt_execute(THD *thd, char *packet, uint packet_length)
         DBUG_VOID_RETURN;
       /* If lex->result is set, mysql_execute_command will use it */
       stmt->lex->result= &cursor->result;
+      thd->lock_id= &cursor->lock_id;
     }
   }
 #ifndef EMBEDDED_LIBRARY
@@ -2069,6 +2070,9 @@ void mysql_stmt_execute(THD *thd, char *packet, uint packet_length)
       Cursor::open is buried deep in JOIN::exec of the top level join.
     */
     cursor->init_from_thd(thd);
+
+    if (cursor->close_at_commit)
+      thd->stmt_map.add_transient_cursor(stmt);
   }
   else
   {
@@ -2078,6 +2082,7 @@ void mysql_stmt_execute(THD *thd, char *packet, uint packet_length)
   }
 
   thd->set_statement(&stmt_backup);
+  thd->lock_id= &thd->main_lock_id;
   thd->current_arena= thd;
   DBUG_VOID_RETURN;
 
@@ -2252,6 +2257,8 @@ void mysql_stmt_fetch(THD *thd, char *packet, uint packet_length)
       the previous calls.
     */
     free_root(cursor->mem_root, MYF(0));
+    if (cursor->close_at_commit)
+      thd->stmt_map.erase_transient_cursor(stmt);
   }
 
   thd->restore_backup_statement(stmt, &stmt_backup);
@@ -2291,14 +2298,6 @@ void mysql_stmt_reset(THD *thd, char *packet)
     DBUG_VOID_RETURN;
 
   stmt->close_cursor();                    /* will reset statement params */
-  cursor= stmt->cursor;
-  if (cursor && cursor->is_open())
-  {
-    thd->change_list= cursor->change_list;
-    cursor->close(FALSE);
-    cleanup_stmt_and_thd_after_use(stmt, thd);
-    free_root(cursor->mem_root, MYF(0));
-  }
 
   stmt->state= Query_arena::PREPARED;
 
@@ -2478,6 +2477,8 @@ void Prepared_statement::close_cursor()
     cursor->close(FALSE);
     cleanup_stmt_and_thd_after_use(this, thd);
     free_root(cursor->mem_root, MYF(0));
+    if (cursor->close_at_commit)
+      thd->stmt_map.erase_transient_cursor(this);
   }
   /*
     Clear parameters from data which could be set by
diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index b333e369dc4..6147a1b62a5 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -1702,10 +1702,12 @@ JOIN::destroy()
 
 Cursor::Cursor(THD *thd)
   :Query_arena(&main_mem_root, INITIALIZED),
-   join(0), unit(0)
+   join(0), unit(0),
+   close_at_commit(FALSE)
 {
   /* We will overwrite it at open anyway. */
   init_sql_alloc(&main_mem_root, ALLOC_ROOT_MIN_BLOCK_SIZE, 0);
+  thr_lock_owner_init(&lock_id, &thd->lock_info);
 }
 
 
@@ -1739,6 +1741,21 @@ Cursor::init_from_thd(THD *thd)
   free_list=	  thd->free_list;
   change_list=    thd->change_list;
   reset_thd(thd);
+  /* Now we have an active cursor and can cause a deadlock */
+  thd->lock_info.n_cursors++;
+
+  close_at_commit= FALSE; /* reset in case we're reusing the cursor */
+  for (TABLE *table= open_tables; table; table= table->next)
+  {
+    const handlerton *ht= table->file->ht;
+    if (ht)
+      close_at_commit|= (ht->flags & HTON_CLOSE_CURSORS_AT_COMMIT);
+    else
+    {
+      close_at_commit= TRUE;     /* handler status is unknown */
+      break;
+    }
+  }
   /*
     XXX: thd->locked_tables is not changed.
     What problems can we have with it if cursor is open?
@@ -1907,6 +1924,7 @@ Cursor::close(bool is_active)
     thd->derived_tables= tmp_derived_tables;
     thd->lock= tmp_lock;
   }
+  thd->lock_info.n_cursors--; /* Decrease the number of active cursors */
   join= 0;
   unit= 0;
   free_items();
diff --git a/sql/sql_select.h b/sql/sql_select.h
index 9285e33be33..7f6d661a4de 100644
--- a/sql/sql_select.h
+++ b/sql/sql_select.h
@@ -392,6 +392,8 @@ class Cursor: public Sql_alloc, public Query_arena
 public:
   Item_change_list change_list;
   select_send result;
+  THR_LOCK_OWNER lock_id;
+  my_bool close_at_commit;
 
   /* Temporary implementation as now we replace THD state by value */
   /* Save THD state into cursor */
diff --git a/tests/mysql_client_test.c b/tests/mysql_client_test.c
index 97138e564a4..ffd99915168 100644
--- a/tests/mysql_client_test.c
+++ b/tests/mysql_client_test.c
@@ -55,6 +55,7 @@ static char current_db[]= "client_test_db";
 static unsigned int test_count= 0;
 static unsigned int opt_count= 0;
 static unsigned int iter_count= 0;
+static my_bool have_innodb= FALSE;
 
 static const char *opt_basedir= "./";
 
@@ -220,6 +221,28 @@ static void print_st_error(MYSQL_STMT *stmt, const char *msg)
   }
 }
 
+/* Check if the connection has InnoDB tables */
+
+static my_bool check_have_innodb(MYSQL *conn)
+{
+  MYSQL_RES *res;
+  MYSQL_ROW row;
+  int rc;
+  my_bool result;
+
+  rc= mysql_query(conn, "show variables like 'have_innodb'");
+  myquery(rc);
+  res= mysql_use_result(conn);
+  DIE_UNLESS(res);
+
+  row= mysql_fetch_row(res);
+  DIE_UNLESS(row);
+
+  result= strcmp(row[1], "YES") == 0;
+  mysql_free_result(res);
+  return result;
+}
+
 
 /*
   This is to be what mysql_query() is for mysql_real_query(), for
@@ -290,6 +313,7 @@ static void client_connect(ulong flag)
   strxmov(query, "USE ", current_db, NullS);
   rc= mysql_query(mysql, query);
   myquery(rc);
+  have_innodb= check_have_innodb(mysql);
 
   if (!opt_silent)
     fprintf(stdout, " OK");
@@ -13749,6 +13773,110 @@ static void test_bug11037()
   myquery(rc);
 }
 
+/* Bug#10760: cursors, crash in a fetch after rollback. */
+
+static void test_bug10760()
+{
+  MYSQL_STMT *stmt;
+  MYSQL_BIND bind[1];
+  int rc;
+  const char *stmt_text;
+  char id_buf[20];
+  ulong id_len;
+  int i= 0;
+  ulong type;
+
+  myheader("test_bug10760");
+
+  mysql_query(mysql, "drop table if exists t1, t2");
+
+  /* create tables */
+  rc= mysql_query(mysql, "create table t1 (id integer not null primary key)"
+                         " engine=MyISAM");
+  myquery(rc);
+  for (; i < 42; ++i)
+  {
+    char buf[100];
+    sprintf(buf, "insert into t1 (id) values (%d)", i+1);
+    rc= mysql_query(mysql, buf);
+    myquery(rc);
+  }
+  mysql_autocommit(mysql, FALSE);
+  /* create statement */
+  stmt= mysql_stmt_init(mysql);
+  type= (ulong) CURSOR_TYPE_READ_ONLY;
+  mysql_stmt_attr_set(stmt, STMT_ATTR_CURSOR_TYPE, (const void*) &type);
+
+  /*
+    1: check that a deadlock within the same connection
+    is resolved and an error is returned. The deadlock is modelled
+    as follows:
+    con1: open cursor for select * from t1;
+    con1: insert into t1 (id) values (1)
+  */
+  stmt_text= "select id from t1 order by 1";
+  rc= mysql_stmt_prepare(stmt, stmt_text, strlen(stmt_text));
+  check_execute(stmt, rc);
+  rc= mysql_stmt_execute(stmt);
+  check_execute(stmt, rc);
+  rc= mysql_query(mysql, "update t1 set id=id+100");
+  DIE_UNLESS(rc);
+  if (!opt_silent)
+    printf("Got error (as expected): %s\n", mysql_error(mysql));
+  /*
+    2: check that MyISAM tables used in cursors survive
+    COMMIT/ROLLBACK.
+  */
+  rc= mysql_rollback(mysql);                  /* should not close the cursor */
+  myquery(rc);
+  rc= mysql_stmt_fetch(stmt);
+  check_execute(stmt, rc);
+
+  /*
+    3: check that cursors to InnoDB tables are closed (for now) by
+    COMMIT/ROLLBACK.
+  */
+  if (! have_innodb)
+  {
+    if (!opt_silent)
+      printf("Testing that cursors are closed at COMMIT/ROLLBACK requires "
+             "InnoDB.\n");
+  }
+  else
+  {
+    stmt_text= "select id from t1 order by 1";
+    rc= mysql_stmt_prepare(stmt, stmt_text, strlen(stmt_text));
+    check_execute(stmt, rc);
+
+    rc= mysql_query(mysql, "alter table t1 engine=InnoDB");
+    myquery(rc);
+
+    bzero(bind, sizeof(bind));
+    bind[0].buffer_type= MYSQL_TYPE_STRING;
+    bind[0].buffer= (void*) id_buf;
+    bind[0].buffer_length= sizeof(id_buf);
+    bind[0].length= &id_len;
+    check_execute(stmt, rc);
+    mysql_stmt_bind_result(stmt, bind);
+
+    rc= mysql_stmt_execute(stmt);
+    rc= mysql_stmt_fetch(stmt);
+    DIE_UNLESS(rc == 0);
+    if (!opt_silent)
+      printf("Fetched row %s\n", id_buf);
+    rc= mysql_rollback(mysql);                  /* should close the cursor */
+    myquery(rc);
+    rc= mysql_stmt_fetch(stmt);
+    DIE_UNLESS(rc);
+    if (!opt_silent)
+      printf("Got error (as expected): %s\n", mysql_error(mysql));
+  }
+
+  mysql_stmt_close(stmt);
+  rc= mysql_query(mysql, "drop table t1");
+  myquery(rc);
+  mysql_autocommit(mysql, TRUE);                /* restore default */
+}
 
 /*
   Read and parse arguments and MySQL options from my.cnf
@@ -13994,6 +14122,7 @@ static struct my_tests_st my_tests[]= {
   { "test_bug9735", test_bug9735 },
   { "test_bug11183", test_bug11183 },
   { "test_bug11037", test_bug11037 },
+  { "test_bug10760", test_bug10760 },
   { 0, 0 }
 };