diff --git a/mysql-test/suite/innodb/r/blob-update-debug.result b/mysql-test/suite/innodb/r/blob-update-debug.result
new file mode 100644
index 00000000000..3eb9d1dcaf5
--- /dev/null
+++ b/mysql-test/suite/innodb/r/blob-update-debug.result
@@ -0,0 +1,15 @@
+#
+# Bug#18185930 UPD_NODE_INSERT_BLOB CAUSES BTR_EXTERN_OWNER_FLAG
+# ASSERTION
+#
+create table t1 (f1 int primary key, f2 blob) engine = innodb;
+insert into t1 values (1, repeat('*', 50000));
+select f1, substring(f2, 1, 40) from t1;
+f1	substring(f2, 1, 40)
+1	****************************************
+set debug = 'd,row_ins_index_entry_timeout';
+update t1 set f1 = 3;
+select f1, substring(f2, 1, 40) from t1;
+f1	substring(f2, 1, 40)
+3	****************************************
+drop table t1;
diff --git a/mysql-test/suite/innodb/t/blob-update-debug.test b/mysql-test/suite/innodb/t/blob-update-debug.test
new file mode 100644
index 00000000000..e12c351e55f
--- /dev/null
+++ b/mysql-test/suite/innodb/t/blob-update-debug.test
@@ -0,0 +1,17 @@
+# This file contains tests involving update operations on blob data type.
+
+--source include/have_innodb.inc
+--source include/have_debug.inc
+
+--echo #
+--echo # Bug#18185930 UPD_NODE_INSERT_BLOB CAUSES BTR_EXTERN_OWNER_FLAG
+--echo # ASSERTION
+--echo #
+
+create table t1 (f1 int primary key, f2 blob) engine = innodb;
+insert into t1 values (1, repeat('*', 50000));
+select f1, substring(f2, 1, 40) from t1;
+set debug = 'd,row_ins_index_entry_timeout';
+update t1 set f1 = 3;
+select f1, substring(f2, 1, 40) from t1;
+drop table t1;
diff --git a/storage/innobase/row/row0ins.c b/storage/innobase/row/row0ins.c
index 7650bc07848..9d5212db6e8 100644
--- a/storage/innobase/row/row0ins.c
+++ b/storage/innobase/row/row0ins.c
@@ -1,6 +1,6 @@
 /*****************************************************************************
 
-Copyright (c) 1996, 2013, Oracle and/or its affiliates. All Rights Reserved.
+Copyright (c) 1996, 2014, Oracle and/or its affiliates. All Rights Reserved.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -2250,6 +2250,10 @@ row_ins_index_entry(
 {
 	ulint	err;
 
+	DBUG_EXECUTE_IF("row_ins_index_entry_timeout", {
+			DBUG_SET("-d,row_ins_index_entry_timeout");
+			return(DB_LOCK_WAIT);});
+
 	if (foreign && UT_LIST_GET_FIRST(index->table->foreign_list)) {
 		err = row_ins_check_foreign_constraints(index->table, index,
 							entry, thr);
diff --git a/storage/innobase/row/row0upd.c b/storage/innobase/row/row0upd.c
index dccfa5ceb5c..825902c4ff2 100644
--- a/storage/innobase/row/row0upd.c
+++ b/storage/innobase/row/row0upd.c
@@ -1769,9 +1769,7 @@ row_upd_clust_rec_by_insert_inherit_func(
 		data += len - BTR_EXTERN_FIELD_REF_SIZE;
 		/* The pointer must not be zero. */
 		ut_a(memcmp(data, field_ref_zero, BTR_EXTERN_FIELD_REF_SIZE));
-		/* The BLOB must be owned. */
-		ut_a(!(data[BTR_EXTERN_LEN] & BTR_EXTERN_OWNER_FLAG));
-
+		data[BTR_EXTERN_LEN] &= ~BTR_EXTERN_OWNER_FLAG;
 		data[BTR_EXTERN_LEN] |= BTR_EXTERN_INHERITED_FLAG;
 		/* The BTR_EXTERN_INHERITED_FLAG only matters in
 		rollback. Purge will always free the extern fields of