http://gwt-code-reviews.appspot.com/962801/diff/1/2 File user/super/com/google/gwt/emul/java/util/AbstractCollection.java (right):
http://gwt-code-reviews.appspot.com/962801/diff/1/2#newcode146 user/super/com/google/gwt/emul/java/util/AbstractCollection.java:146: sb.append(value == this ? "(this Collection)" : String.valueOf(value)); This only catches direct loops -- it won't catch A -> [ B -> [A, C] ] or various other forms. Do we want to instead keep an identity set of seen elements? http://gwt-code-reviews.appspot.com/962801/show -- http://groups.google.com/group/Google-Web-Toolkit-Contributors