do not allow nested arrays in whereIn method

src/Illuminate/Database/Query/Builder.php

@@ -1028,6 +1028,10 @@ public function whereIn($column, $values, $boolean = 'and', $not = false)
 
         $this->wheres[] = compact('type', 'column', 'values', 'boolean');
 
+        if (count($values) !== count(Arr::flatten($values, 1))) {
+            throw new InvalidArgumentException("Nested arrays may not be passed to whereIn method.");
+        }
+
         // Finally, we'll add a binding for each value unless that value is an expression
         // in which case we will just skip over it since it will be the query as a raw
         // string and not as a parameterized place-holder to be replaced by the PDO.