Fix problem parsing ill-formed URI query parameters such as "?&a".

lib/rdf/model/uri.rb

@@ -1240,17 +1240,18 @@ def query_values(return_type=Hash)
       query.to_s.split('&').
         inject(return_type == Hash ? {} : []) do |memo,kv|
           k,v = kv.to_s.split('=', 2)
-          next if k.to_s.empty?
-          k = CGI.unescape(k)
-          v = CGI.unescape(v) if v
-          if return_type == Hash
-            case memo[k]
-            when nil then memo[k] = v
-            when Array then memo[k] << v
-            else memo[k] = [memo[k], v]
+          unless k.to_s.empty?
+            k = CGI.unescape(k)
+            v = CGI.unescape(v) if v
+            if return_type == Hash
+              case memo[k]
+              when nil then memo[k] = v
+              when Array then memo[k] << v
+              else memo[k] = [memo[k], v]
+              end
+            else
+              memo << [k, v].compact
             end
-          else
-            memo << [k, v].compact
           end
           memo
         end

spec/model_uri_spec.rb

@@ -749,6 +749,7 @@
       "?one.two.three=four" => {"one.two.three" => "four"},
       "?one[two][three]=four&one[two][five]=six" => {"one[two][three]" => "four", "one[two][five]" => "six"},
       "?one=two&one=three&one=four" => {'one' => ['two', 'three', 'four']},
+      "?&a" => {'a' => nil},
     }.each do |uri, result|
       it uri do
         if result