- make it possible to provide defaults for <multikey name="+"> and

  <key name="+">; keys need to be provided for each default value
- fix bug in converting an empty section that contained a
  <multikey name="+">
- document <default> element in reference manual and DTD
- more tests

doc/ZConfig/schema.dtd

@@ -10,6 +10,10 @@
   WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
   FOR A PARTICULAR PURPOSE.
   *************************************************************************
+
+  Please note that not all documents that conform to this DTD are
+  legal ZConfig schema.  The ZConfig reference manual describes many
+  constraints that are important to understanding ZConfig schema.
   -->
 
 <!-- DTD for ZConfig schema documents. -->
@@ -61,7 +65,11 @@
           name       NMTOKEN  #REQUIRED
           prefix     NMTOKEN  #IMPLIED>
 
-<!ELEMENT key (description?, metadefault?, example?)>
+<!ELEMENT default    (#PCDATA)*>
+<!ATTLIST default
+          key        CDATA    #IMPLIED>
+
+<!ELEMENT key (description?, metadefault?, example?, default*)>
 <!ATTLIST key
           name       CDATA    #REQUIRED
           attribute  NMTOKEN  #IMPLIED

doc/ZConfig/zconfig.tex

@@ -613,6 +613,22 @@ The following elements are used to describe a schema:
 \end{elementdesc}
 
 
+\begin{elementdesc}{default}{PCDATA}
+  Each \element{default} element specifies a single default value for
+  a \element{multikey}.  This element can be repeated to produce a
+  list of individual default values.  The text contained in the
+  element will be passed to the datatype conversion for the
+  \element{multikey}.
+
+  \begin{attributedesc}{key}{}
+    Key to associate with the default value.  This is only used for
+    defaults of a \element{key} or \element{multikey} with a
+    \attribute{name} of \code{+}; in that case this attribute is
+    required.
+  \end{attributedesc}
+\end{elementdesc}
+
+
 \begin{elementdesc}{section}{description?}
   A \element{section} element is used to describe a section which may
   occur at most once in the section type or top-level schema in which