MDEV-16038 Assertion `map->n_bits > 0' failed (my_bitmap.c:386: bitmap_is_clear_all)

Rows with no elements are not allowed in a table value constructor
unless it is used in an INSERT statement.

mysql-test/main/table_value_constr.result

@@ -2072,7 +2072,7 @@ select * from (values (1), (t1.b), (2)) as new_tvc;
 ERROR HY000: Field reference 't1.b' can't be used in table value constructor
 drop table t1;
 #
-# MDEV-MDEV-15940: cursor over TVC
+# MDEV-15940: cursor over TVC
 #
 BEGIN NOT ATOMIC
 DECLARE v INT;
@@ -2092,3 +2092,8 @@ END;
 |
 v
 1
+#
+# MDEV-16038: empty row in TVC
+#
+with t as (values (),()) select 1 from t;
+ERROR HY000: Row with no elements is not allowed in table value constructor in this context

mysql-test/main/table_value_constr.test

@@ -1046,7 +1046,7 @@ select * from (values (1), (t1.b), (2)) as new_tvc;
 drop table t1;
 
 --echo #
---echo # MDEV-MDEV-15940: cursor over TVC
+--echo # MDEV-15940: cursor over TVC
 --echo #
 
 DELIMITER |;
@@ -1068,3 +1068,10 @@ END;
 |
 
 DELIMITER ;|
+
+--echo #
+--echo # MDEV-16038: empty row in TVC
+--echo #
+
+--error ER_EMPTY_ROW_IN_TVC
+with t as (values (),()) select 1 from t;

sql/share/errmsg-utf8.txt

@@ -7913,3 +7913,5 @@ ER_INDEX_FILE_FULL
         eng "The index file for table '%-.192s' is full"
 ER_UPDATED_COLUMN_ONLY_ONCE
         eng "The column %`s.%`s cannot be changed more than once in a single UPDATE statement"
+ER_EMPTY_ROW_IN_TVC
+        eng "Row with no elements is not allowed in table value constructor in this context"

sql/sql_tvc.cc

@@ -221,6 +221,12 @@ bool table_value_constr::prepare(THD *thd, SELECT_LEX *sl,
   uint cnt= first_elem->elements;
   Type_holder *holders;
   
+  if (cnt == 0)
+  {
+    my_error(ER_EMPTY_ROW_IN_TVC, MYF(0));
+    DBUG_RETURN(true);
+  }
+
   if (fix_fields_for_tvc(thd, li))
     DBUG_RETURN(true);