update method signature and use force fill

Author: taylorotwell

Diff for: src/Illuminate/Database/Eloquent/Model.php

@@ -410,7 +410,7 @@ protected function incrementOrDecrement($column, $amount, $extra, $method)
             return $query->{$method}($column, $amount, $extra);
         }
 
-        $this->incrementOrDecrementAttributeValue($column, $amount, $method, $extra);
+        $this->incrementOrDecrementAttributeValue($column, $amount, $extra, $method);
 
         return $query->where(
             $this->getKeyName(), $this->getKey()
@@ -422,13 +422,15 @@ protected function incrementOrDecrement($column, $amount, $extra, $method)
      *
      * @param  string  $column
      * @param  int  $amount
+     * @param  array  $extra
      * @param  string  $method
      * @return void
      */
-    protected function incrementOrDecrementAttributeValue($column, $amount, $method, $extra = [])
+    protected function incrementOrDecrementAttributeValue($column, $amount, $extra, $method)
     {
         $this->{$column} = $this->{$column} + ($method == 'increment' ? $amount : $amount * -1);
-        $this->fill($extra);
+
+        $this->forceFill($extra);
 
         $this->syncOriginalAttribute($column);
     }