diff --git a/core/src/main/java/hudson/Util.java b/core/src/main/java/hudson/Util.java
index 971b689578..ba25ae8317 100644
--- a/core/src/main/java/hudson/Util.java
+++ b/core/src/main/java/hudson/Util.java
@@ -733,7 +733,12 @@ public class Util {
      * but don't remember it right now.
      *
      * @since 1.204
+     * @deprecated This method is broken (see ISSUE#1666). It should probably
+     * be removed but I'm not sure if it is considered part of the public API
+     * that needs to be maintained for backwards compatibility.
+     * Use {@link #encode(String)} instead. 
      */
+    @Deprecated
     public static String encodeRFC2396(String url) {
         try {
             return new URI(null,url,null).toASCIIString();
diff --git a/core/src/main/java/hudson/model/AbstractItem.java b/core/src/main/java/hudson/model/AbstractItem.java
index 12897871bb..8a9af12144 100644
--- a/core/src/main/java/hudson/model/AbstractItem.java
+++ b/core/src/main/java/hudson/model/AbstractItem.java
@@ -150,7 +150,7 @@ public abstract class AbstractItem extends Actionable implements Item, HttpDelet
         StaplerRequest request = Stapler.getCurrentRequest();
         if(request==null)
             throw new IllegalStateException("Not processing a HTTP request");
-        return Util.encodeRFC2396(request.getRootPath()+'/'+getUrl());
+        return Util.encode(request.getRootPath()+'/'+getUrl());
     }
 
     /**
diff --git a/core/src/main/resources/hudson/tasks/test/AbstractTestResultAction/summary.jelly b/core/src/main/resources/hudson/tasks/test/AbstractTestResultAction/summary.jelly
index b1a3cf35a7..acc11135e2 100644
--- a/core/src/main/resources/hudson/tasks/test/AbstractTestResultAction/summary.jelly
+++ b/core/src/main/resources/hudson/tasks/test/AbstractTestResultAction/summary.jelly
@@ -38,7 +38,7 @@
           <li class="${elementClass}" style="${elementStyle}">
             <!-- child test results are referenced from their parent builds -->
             <j:set var="build" value="${testObject.owner}" />
-            <a href="${build.absoluteUrl}/${build.testResultAction.urlName}/${testObject.getRelativePathFrom(null)}">
+            <a href="${build.absoluteUrl}${build.testResultAction.urlName}/${testObject.getRelativePathFrom(null)}">
               ${testObject.fullName}
             </a>
           </li>