Unbork handling of objects with no primary key. Added a comment indicating

where we will need to cache the results of a modifier (like an insert or an
update). Added hasPrimaryKey() to DepotMarshaller which we will soon use
externally.


git-svn-id: https://samskivert.googlecode.com/svn/trunk@1927 6335cc39-0255-0410-8fd6-9bcaacd3b74c

src/java/com/samskivert/jdbc/depot/DepotMarshaller.java

@@ -173,6 +173,14 @@ public class DepotMarshaller<T>
         return _tableName;
     }
 
+    /**
+     * Returns true if our persistent object defines a primary key.
+     */
+    public boolean hasPrimaryKey ()
+    {
+        return (_primaryKey != null);
+    }
+
     /**
      * Returns a key configured with the primary key of the supplied object.
      * Throws an exception if the persistent object did not declare a primary
@@ -180,7 +188,7 @@ public class DepotMarshaller<T>
      */
     public DepotRepository.Key getPrimaryKey (Object object)
     {
-        if (_primaryKey == null) {
+        if (!hasPrimaryKey()) {
             throw new UnsupportedOperationException(
                 getClass().getName() + " does not define a primary key");
         }
@@ -338,7 +346,7 @@ public class DepotMarshaller<T>
         throws SQLException
     {
         // if we have no primary key or no generator, then we're done
-        if (_primaryKey == null || _keyGenerator == null) {
+        if (!hasPrimaryKey() || _keyGenerator == null) {
             return;
         }