diff --git a/mysql-test/suite/innodb/r/cursor-restore-unique-null.result b/mysql-test/suite/innodb/r/cursor-restore-unique-null.result
new file mode 100644
index 00000000000..b5e2de88e7a
--- /dev/null
+++ b/mysql-test/suite/innodb/r/cursor-restore-unique-null.result
@@ -0,0 +1,24 @@
+CREATE TABLE t(a INT PRIMARY KEY, b INT, c INT, UNIQUE KEY `b_c` (`b`,`c`))
+ENGINE=InnoDB, STATS_PERSISTENT=0;
+INSERT INTO t SET a = 1, c = 2;
+connect con1,localhost,root;
+BEGIN;
+INSERT INTO t SET a=2, c=2;
+connection default;
+BEGIN;
+SET DEBUG_SYNC="lock_wait_suspend_thread_enter SIGNAL select_locked";
+SELECT * FROM t FORCE INDEX(b) FOR UPDATE;
+connection con1;
+SET DEBUG_SYNC="now WAIT_FOR select_locked";
+ROLLBACK;
+connection default;
+# If the bug is not fixed, and the both unique index key fields are
+# NULL, there will be two (1, NULL, 2) rows in the result,
+# because cursor will be restored to (NULL, 2, 1) position for
+# secondary key instead of "supremum".
+a	b	c
+1	NULL	2
+COMMIT;
+SET DEBUG_SYNC="RESET";
+disconnect con1;
+DROP TABLE t;
diff --git a/mysql-test/suite/innodb/t/cursor-restore-unique-null.test b/mysql-test/suite/innodb/t/cursor-restore-unique-null.test
new file mode 100644
index 00000000000..c22ddf89d8f
--- /dev/null
+++ b/mysql-test/suite/innodb/t/cursor-restore-unique-null.test
@@ -0,0 +1,36 @@
+--source include/have_innodb.inc
+--source include/have_debug.inc
+--source include/have_debug_sync.inc
+--source include/count_sessions.inc
+
+
+CREATE TABLE t(a INT PRIMARY KEY, b INT, c INT, UNIQUE KEY `b_c` (`b`,`c`))
+  ENGINE=InnoDB, STATS_PERSISTENT=0;
+INSERT INTO t SET a = 1, c = 2;
+
+--connect con1,localhost,root
+BEGIN;
+  INSERT INTO t SET a=2, c=2;
+
+--connection default
+BEGIN;
+SET DEBUG_SYNC="lock_wait_suspend_thread_enter SIGNAL select_locked";
+--send SELECT * FROM t FORCE INDEX(b) FOR UPDATE
+
+--connection con1
+SET DEBUG_SYNC="now WAIT_FOR select_locked";
+ROLLBACK;
+
+--connection default
+--echo # If the bug is not fixed, and the both unique index key fields are
+--echo # NULL, there will be two (1, NULL, 2) rows in the result,
+--echo # because cursor will be restored to (NULL, 2, 1) position for
+--echo # secondary key instead of "supremum".
+--reap
+COMMIT;
+
+SET DEBUG_SYNC="RESET";
+
+--disconnect con1
+DROP TABLE t;
+--source include/wait_until_count_sessions.inc
diff --git a/storage/innobase/btr/btr0pcur.cc b/storage/innobase/btr/btr0pcur.cc
index 90084ef4379..4296d94fe5e 100644
--- a/storage/innobase/btr/btr0pcur.cc
+++ b/storage/innobase/btr/btr0pcur.cc
@@ -453,8 +453,15 @@ btr_pcur_t::restore_position(ulint restore_latch_mode, const char *file,
 
 			return SAME_ALL;
 		}
-		if (n_matched_fields >= index->n_uniq)
-			ret_val= SAME_UNIQ;
+		if (n_matched_fields >= index->n_uniq
+		    /* Unique indexes can contain "NULL" keys, and if all
+		    unique fields are NULL and not all tuple
+		    fields match to record fields, then treat it as if
+		    restored cursor position points to the record with
+		    not the same unique key. */
+		    && !(index->n_nullable
+			    && dtuple_contains_null(tuple, index->n_uniq)))
+			  ret_val= SAME_UNIQ;
 	}
 
 	mem_heap_free(heap);
diff --git a/storage/innobase/dict/dict0dict.cc b/storage/innobase/dict/dict0dict.cc
index d0f8ac21dd8..26671d85b3d 100644
--- a/storage/innobase/dict/dict0dict.cc
+++ b/storage/innobase/dict/dict0dict.cc
@@ -1849,7 +1849,6 @@ dict_index_add_to_cache(
 	new_index->n_fields = new_index->n_def;
 	new_index->trx_id = index->trx_id;
 	new_index->set_committed(index->is_committed());
-	new_index->nulls_equal = index->nulls_equal;
 #ifdef MYSQL_INDEX_DISABLE_AHI
 	new_index->disable_ahi = index->disable_ahi;
 #endif
diff --git a/storage/innobase/include/data0data.h b/storage/innobase/include/data0data.h
index c2b8c3e00b6..a2c39ecaed8 100644
--- a/storage/innobase/include/data0data.h
+++ b/storage/innobase/include/data0data.h
@@ -349,15 +349,12 @@ dtuple_set_types_binary(
 	dtuple_t*	tuple,	/*!< in: data tuple */
 	ulint		n)	/*!< in: number of fields to set */
 	MY_ATTRIBUTE((nonnull));
-/**********************************************************************//**
-Checks if a dtuple contains an SQL null value.
-@return TRUE if some field is SQL null */
+/** Checks if a dtuple contains an SQL null value.
+@param tuple tuple
+@param fields_number number of fields in the tuple to check
+@return true if some field is SQL null */
 UNIV_INLINE
-ibool
-dtuple_contains_null(
-/*=================*/
-	const dtuple_t*	tuple)	/*!< in: dtuple */
-	MY_ATTRIBUTE((nonnull, warn_unused_result));
+bool dtuple_contains_null(const dtuple_t *tuple, ulint fields_number = 0);
 /**********************************************************//**
 Checks that a data field is typed. Asserts an error if not.
 @return TRUE if ok */
diff --git a/storage/innobase/include/data0data.inl b/storage/innobase/include/data0data.inl
index 39ade7b1e09..f4ae7528d3f 100644
--- a/storage/innobase/include/data0data.inl
+++ b/storage/innobase/include/data0data.inl
@@ -599,28 +599,18 @@ data_write_sql_null(
 	memset(data, 0, len);
 }
 
-/**********************************************************************//**
-Checks if a dtuple contains an SQL null value.
-@return TRUE if some field is SQL null */
+/** Checks if a dtuple contains an SQL null value.
+@param tuple tuple
+@param fields_number number of fields in the tuple to check
+@return true if some field is SQL null */
 UNIV_INLINE
-ibool
-dtuple_contains_null(
-/*=================*/
-	const dtuple_t*	tuple)	/*!< in: dtuple */
+bool dtuple_contains_null(const dtuple_t *tuple, ulint fields_number)
 {
-	ulint	n;
-	ulint	i;
-
-	n = dtuple_get_n_fields(tuple);
-
-	for (i = 0; i < n; i++) {
-		if (dfield_is_null(dtuple_get_nth_field(tuple, i))) {
-
-			return(TRUE);
-		}
-	}
-
-	return(FALSE);
+  ulint n= fields_number ? fields_number : dtuple_get_n_fields(tuple);
+  for (ulint i= 0; i < n; i++)
+    if (dfield_is_null(dtuple_get_nth_field(tuple, i)))
+      return true;
+  return false;
 }
 
 /**************************************************************//**
diff --git a/storage/innobase/include/dict0mem.h b/storage/innobase/include/dict0mem.h
index f0d4eb7bebf..d81bbb51b43 100644
--- a/storage/innobase/include/dict0mem.h
+++ b/storage/innobase/include/dict0mem.h
@@ -1011,8 +1011,6 @@ struct dict_index_t {
 				/*!< number of columns the user defined to
 				be in the index: in the internal
 				representation we add more columns */
-	unsigned	nulls_equal:1;
-				/*!< if true, SQL NULL == SQL NULL */
 #ifdef BTR_CUR_HASH_ADAPT
 #ifdef MYSQL_INDEX_DISABLE_AHI
  	unsigned	disable_ahi:1;
diff --git a/storage/innobase/include/dict0mem.inl b/storage/innobase/include/dict0mem.inl
index 090ec73278b..28900c9062f 100644
--- a/storage/innobase/include/dict0mem.inl
+++ b/storage/innobase/include/dict0mem.inl
@@ -63,7 +63,6 @@ dict_mem_fill_index_struct(
 	index->n_core_fields = (unsigned int) n_fields;
 	/* The '1 +' above prevents allocation
 	of an empty mem block */
-	index->nulls_equal = false;
 #ifdef BTR_CUR_HASH_ADAPT
 #ifdef MYSQL_INDEX_DISABLE_AHI
 	index->disable_ahi = false;
diff --git a/storage/innobase/row/row0ins.cc b/storage/innobase/row/row0ins.cc
index 088981e5b5b..6e68f46825a 100644
--- a/storage/innobase/row/row0ins.cc
+++ b/storage/innobase/row/row0ins.cc
@@ -2038,7 +2038,7 @@ row_ins_dupl_error_with_rec(
 	/* In a unique secondary index we allow equal key values if they
 	contain SQL NULLs */
 
-	if (!dict_index_is_clust(index) && !index->nulls_equal) {
+	if (!dict_index_is_clust(index)) {
 
 		for (i = 0; i < n_unique; i++) {
 			if (dfield_is_null(dtuple_get_nth_field(entry, i))) {
@@ -2143,16 +2143,8 @@ row_ins_scan_sec_index_for_duplicate(
 	/* If the secondary index is unique, but one of the fields in the
 	n_unique first fields is NULL, a unique key violation cannot occur,
 	since we define NULL != NULL in this case */
-
-	if (!index->nulls_equal) {
-		for (ulint i = 0; i < n_unique; i++) {
-			if (UNIV_SQL_NULL == dfield_get_len(
-					dtuple_get_nth_field(entry, i))) {
-
-				DBUG_RETURN(DB_SUCCESS);
-			}
-		}
-	}
+	if (index->n_nullable && dtuple_contains_null(entry, n_unique))
+		DBUG_RETURN(DB_SUCCESS);
 
 	/* Store old value on n_fields_cmp */