added an option to force the deletion of a attachment

lib/couchrest/core/database.rb

@@ -113,10 +113,21 @@ module CouchRest
     end
     
     # DELETE an attachment directly from CouchDB
-    def delete_attachment doc, name
+    def delete_attachment(doc, name, force=false)
       uri = url_for_attachment(doc, name)
       # this needs a rev
-      JSON.parse(HttpAbstraction.delete(uri))
+      begin
+        JSON.parse(HttpAbstraction.delete(uri))
+      rescue Exception => error
+        if force
+          # get over a 409
+          doc = get(doc['_id'])
+          uri = url_for_attachment(doc, name)
+          JSON.parse(HttpAbstraction.delete(uri))
+        else
+          error
+        end
+      end
     end
     
     # Save a document to CouchDB. This will use the <tt>_id</tt> field from

lib/couchrest/mixins/attachments.rb

@@ -19,9 +19,9 @@ module CouchRest
       end
 
       # deletes an attachment directly from couchdb
-      def delete_attachment(name)
+      def delete_attachment(name, force=false)
         raise ArgumentError, "doc.database required to delete_attachment" unless database
-        result = database.delete_attachment(self, name)
+        result = database.delete_attachment(self, name, force)
         self['_rev'] = result['rev']
         result['ok']
       end

spec/couchrest/core/database_spec.rb

@@ -372,6 +372,15 @@ describe CouchRest::Database do
       @doc = @db.get('mydocwithattachment') # avoid getting a 409
       lambda{ @db.fetch_attachment(@doc,'test.html')}.should raise_error
     end
+    
+    it "should force a delete even if we get a 409" do
+      @doc['new_attribute'] = 'something new'
+      @db.put_attachment(@doc, 'test', File.open(File.join(File.dirname(__FILE__), '..', '..', 'fixtures', 'attachments', 'test.html')).read)
+      # at this point the revision number changed, if we try to save doc one more time
+      # we would get a 409.
+      lambda{ @db.save_doc(@doc) }.should raise_error
+      lambda{ @db.delete_attachment(@doc, "test", true) }.should_not raise_error
+    end
   end
 
   describe "POST document with attachment (with funky name)" do