Merge r1067 from branches/5.0:

trx_rollback_for_mysql(), trx_commit_for_mysql():
Protect the creation of trx_dummy_sess with kernel_mutex.
This error was introduced in r1046 and r1050.

srv/srv0start.c

@@ -1624,11 +1624,6 @@ innobase_start_or_create_for_mysql(void)
 		return((int)DB_ERROR);
 	}
 
-	/* Create the master thread which does purge and other utility
-	operations */
-
-	os_thread_create(&srv_master_thread, NULL, thread_ids
-			 + (1 + SRV_MAX_N_IO_THREADS));
 #ifdef UNIV_DEBUG
 	/* buf_debug_prints = TRUE; */
 #endif /* UNIV_DEBUG */
@@ -1736,6 +1731,29 @@ innobase_start_or_create_for_mysql(void)
 
 	fflush(stderr);
 
+	/* Advance the lsn and make a checkpoint so that if mysqld crashes
+	very quickly after the startup, InnoDB in the next startup notices
+	the mismatch in the lsn in the checkpoint and in ibdata1, and knows
+	that a crash recovery is needed. */
+
+	mutex_enter(&kernel_mutex);
+
+	/* This call advances the lsn because it writes the new trx id to
+	the trx sys header in ibdata1 */
+	trx_sys_get_new_trx_id();
+
+	mutex_exit(&kernel_mutex);
+
+	printf("DOING CHECKPOINT\n");
+
+	log_checkpoint(TRUE, FALSE);
+
+	/* Create the master thread which does purge and other utility
+	operations */
+
+	os_thread_create(&srv_master_thread, NULL, thread_ids
+			 + (1 + SRV_MAX_N_IO_THREADS));
+
 	if (trx_doublewrite_must_reset_space_ids) {
 		/* Actually, we did not change the undo log format between
 		4.0 and 4.1.1, and we would not need to run purge to

trx/trx0roll.c

@@ -135,6 +135,8 @@ trx_rollback_for_mysql(
 	the transaction object does not have an InnoDB session object, and we
 	set a dummy session that we use for all MySQL transactions. */
 
+	mutex_enter(&kernel_mutex);
+
 	if (trx->sess == NULL) {
 		/* Open a dummy session */
 
@@ -145,6 +147,8 @@ trx_rollback_for_mysql(
 		trx->sess = trx_dummy_sess;
 	}
 
+	mutex_exit(&kernel_mutex);
+
 	err = trx_general_rollback_for_mysql(trx, FALSE, NULL);
 	
 	trx->op_info = "";

trx/trx0trx.c

@@ -1602,6 +1602,8 @@ trx_commit_for_mysql(
 	the transaction object does not have an InnoDB session object, and we
 	set the dummy session that we use for all MySQL transactions. */
 
+	mutex_enter(&kernel_mutex);
+
 	if (trx->sess == NULL) {
 		/* Open a dummy session */
 
@@ -1612,6 +1614,8 @@ trx_commit_for_mysql(
 		trx->sess = trx_dummy_sess;
 	}
 	
+	mutex_exit(&kernel_mutex);
+
 	trx_start_if_not_started(trx);
 
 	mutex_enter(&kernel_mutex);