Fix for LP#702786 "Two handler read f1 next gives different errors"

mysql-test/suite/handler/heap.result:
  New test case
mysql-test/suite/handler/heap.test:
  New test case
sql/sql_handler.cc:
  If we get a fatal error in handler read, end table/index scan as it's likely it was wrongly used (for example not supported feature for index)

sql/sql_handler.cc

@@ -819,6 +819,7 @@ retry:
                           "table '%s'",
                           error, tables->table_name);
         table->file->print_error(error,MYF(0));
+        table->file->ha_index_or_rnd_end();
         goto err;
       }
       goto ok;