Index: src/main/java/com/xpn/xwiki/user/impl/xwiki/XWikiAuthServiceImpl.java
===================================================================
--- src/main/java/com/xpn/xwiki/user/impl/xwiki/XWikiAuthServiceImpl.java	(revision 17694)
+++ src/main/java/com/xpn/xwiki/user/impl/xwiki/XWikiAuthServiceImpl.java	(working copy)
@@ -45,6 +45,7 @@
 import com.xpn.xwiki.plugin.ldap.LDAPPlugin;
 import com.xpn.xwiki.user.api.XWikiAuthService;
 import com.xpn.xwiki.user.api.XWikiUser;
+import com.xpn.xwiki.util.Util;
 
 public class XWikiAuthServiceImpl extends AbstractXWikiAuthService
 {
@@ -160,9 +161,9 @@
 
                 MyFilterConfig fconfig = new MyFilterConfig();
                 if (xwiki.Param("xwiki.authentication.loginsubmitpage") != null) {
-                    fconfig.setInitParameter("loginSubmitPattern", xwiki.Param("xwiki.authentication.loginsubmitpage"));
+                    fconfig.setInitParameter(FormAuthenticator.LOGIN_SUBMIT_PATTERN_KEY, xwiki.Param("xwiki.authentication.loginsubmitpage"));
                 } else {
-                    fconfig.setInitParameter("loginSubmitPattern", "/loginsubmit/XWiki/XWikiLogin");
+                    fconfig.setInitParameter(FormAuthenticator.LOGIN_SUBMIT_PATTERN_KEY, "/loginsubmit/XWiki/XWikiLogin");
                 }
 
                 this.authenticator.init(fconfig, sconfig);
@@ -569,6 +570,6 @@
         if (contextPath.endsWith("/") && !contextPath.startsWith("/")) {
             contextPath = "/" + StringUtils.chop(contextPath);
         }
-        return StringUtils.removeStart(context.getURLFactory().getURL(url, context), contextPath);
+        return StringUtils.removeStart(context.getURLFactory().getURL(url, context), Util.escapeURL(contextPath));
     }
 }