FELIX-4406 fail validation with null provide

git-svn-id: https://svn.apache.org/repos/asf/felix/trunk@1602639 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/scr/src/main/java/org/apache/felix/scr/impl/metadata/ServiceMetadata.java b/scr/src/main/java/org/apache/felix/scr/impl/metadata/ServiceMetadata.java
index 7c6f62c..62f7319 100644
--- a/scr/src/main/java/org/apache/felix/scr/impl/metadata/ServiceMetadata.java
+++ b/scr/src/main/java/org/apache/felix/scr/impl/metadata/ServiceMetadata.java
@@ -102,6 +102,14 @@
             throw componentMetadata
                 .validationFailure( "At least one provided interface must be declared in the service element" );
         }
+        for ( String provide: m_provides )
+        {
+        	if ( provide == null )
+        	{
+                throw componentMetadata
+                    .validationFailure( "Null provides.  Possibly service is not specified as value of attribute 'interface'" );
+        	}
+        }
         if (m_serviceFactory != null)
         {
         	if (componentMetadata.getNamespaceCode() >= XmlHandler.DS_VERSION_1_3)