From 996a073eae9925c6cde0a765fbc7798727738a28 Mon Sep 17 00:00:00 2001
From: Sai <github@saizai.com>
Date: Thu, 23 Jan 2014 16:26:09 -0500
Subject: [PATCH] #dup with unslugged model causes undefined method error

In lib/friendly_id/base.rb:252:

```
    def dup
      super.tap { |duplicate| duplicate.slug = nil }
    end
```

However, suppose we have a User with just `friendly_id :login` - no extra slug. #slug= is not defined, and therefore some_user.dup fails.

My patch just makes the dup check if slug= is defined before using it.
---
 lib/friendly_id/base.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/friendly_id/base.rb b/lib/friendly_id/base.rb
index 5e10762f3..18195c8bf 100644
--- a/lib/friendly_id/base.rb
+++ b/lib/friendly_id/base.rb
@@ -249,7 +249,7 @@ def to_param
 
     # Clears slug on duplicate records when calling `dup`.
     def dup
-      super.tap { |duplicate| duplicate.slug = nil }
+      super.tap { |duplicate| duplicate.slug = nil if duplicate.respond_to?('slug=') }
     end
   end
 end