fix utils.inspect's detection of circular structures

lib/util.js

@@ -145,8 +145,6 @@ exports.inspect = function (obj, showHidden, depth, colors) {
       base = ' ' + value.toUTCString();
     }
 
-    seen.push(value);
-
     if (keys.length === 0) {
       return braces[0] + base + braces[1];
     }
@@ -159,6 +157,8 @@ exports.inspect = function (obj, showHidden, depth, colors) {
       }
     }
 
+    seen.push(value);
+
     var output = keys.map(function (key) {
       var name, str;
       if (value.__lookupGetter__) {
@@ -218,6 +218,8 @@ exports.inspect = function (obj, showHidden, depth, colors) {
       return name + ": " + str;
     });
 
+    seen.pop();
+
     var numLinesEst = 0;
     var length = output.reduce(function(prev, cur) {
         numLinesEst++;