Filter Lists with empty default view URLs

Such lists do not cause much trouble now, other than the fact they don't
work and produce an odd link.  Most of what this change is doing is
saying, "We don't support this." In the future, we may add support for
such things (maybe while trying to solve various issues with Views in
general).
diff --git a/src/com/google/enterprise/adaptor/sharepoint/SharePointAdaptor.java b/src/com/google/enterprise/adaptor/sharepoint/SharePointAdaptor.java
index 7a65260..31e186d 100644
--- a/src/com/google/enterprise/adaptor/sharepoint/SharePointAdaptor.java
+++ b/src/com/google/enterprise/adaptor/sharepoint/SharePointAdaptor.java
@@ -1367,6 +1367,16 @@
       if (w.getLists() != null) {
         writer.startSection(ObjectType.LIST);
         for (Lists.List list : w.getLists().getList()) {
+          if ("".equals(list.getDefaultViewUrl())) {
+            // Do some I/O to give a good informational message. This is
+            // expected to be a very rare case.
+            com.microsoft.schemas.sharepoint.soap.List l
+                = siteDataClient.getContentList(list.getID());
+            log.log(Level.INFO,
+                "Ignoring List {0} in {1}, since it has no default view URL",
+                new Object[] {l.getMetadata().getTitle(), webUrl});
+            continue;
+          }
           writer.addLink(encodeDocId(list.getDefaultViewUrl()),
               list.getDefaultViewUrl());
         }