Added comment to help keep a record of why inner evaluation is skipped

src/subscribables/dependentObservable.js

@@ -59,8 +59,13 @@ ko.dependentObservable = function (evaluatorFunctionOrOptions, evaluatorFunction
     }
 
     function evaluateImmediate() {
-        if (_isBeingEvaluated)
+        if (_isBeingEvaluated) {
+            // If the evaluation of a ko.computed causes side effects, it's possible that it will trigger its own re-evaluation.
+            // This is not desirable (it's hard for a developer to realise a chain of dependencies might cause this, and they almost
+            // certainly didn't intend infinite re-evaluations). So, for predictability, we simply prevent ko.computeds from causing
+            // their own re-evaluation. Further discussion at https://github.com/SteveSanderson/knockout/pull/387
             return;
+        }
 
         // Don't dispose on first evaluation, because the "disposeWhen" callback might
         // e.g., dispose when the associated DOM element isn't in the doc, and it's not