Add some testing for AbstractResponse#return! and fix the generic fallback exception that gets raised.

In some versions of Ruby, a parenthesis ambiguity warning would be emitted:
  [...] ruby/1.8/gems/rest-client-1.6.1/lib/restclient/abstract_response.rb:50: warning: parenthesize argument(s) for future version
Better to be unambiguous about the exception and include the response code too.

lib/restclient/abstract_response.rb

@@ -31,7 +31,7 @@ module RestClient
 
     # Return the default behavior corresponding to the response code:
     # the response itself for code in 200..206, redirection for 301, 302 and 307 in get and head cases, redirection for 303 and an exception in other cases
-    def return! request  = nil, result = nil, & block
+    def return! request = nil, result = nil, & block
       if (200..207).include? code
         self
       elsif [301, 302, 307].include? code
@@ -47,7 +47,7 @@ module RestClient
       elsif Exceptions::EXCEPTIONS_MAP[code]
         raise Exceptions::EXCEPTIONS_MAP[code].new(self, code)
       else
-        raise RequestFailed self
+        raise RequestFailed.new(self, code)
       end
     end
 

spec/abstract_response_spec.rb

@@ -64,4 +64,22 @@ describe RestClient::AbstractResponse do
   it "can access the net http result directly" do
     @response.net_http_res.should == @net_http_res
   end
+  
+  describe "#return!" do
+    it "should return the response itself on 200-codes" do
+      @net_http_res.should_receive(:code).and_return('200')
+      @response.return!.should be_equal(@response)
+    end
+
+    it "should raise RequestFailed on unknown codes" do
+      @net_http_res.should_receive(:code).and_return('1000')
+      lambda { @response.return! }.should raise_error RestClient::RequestFailed
+    end
+    
+    it "should raise an error on a redirection after non-GET/HEAD requests" do
+      @net_http_res.should_receive(:code).and_return('301')
+      @response.args.merge(:method => :put)
+      lambda { @response.return! }.should raise_error RestClient::RequestFailed
+    end
+  end
 end