Don't use SGML empty tags

For DocBook XML compatibility, don't use SGML empty tags (</>) anymore,
replace by the full tag name.  Add a warning option to catch future
occurrences.

Alexander Lakhin, Jürgen Purtz

doc/src/sgml/xml2.sgml

@@ -8,7 +8,7 @@
  </indexterm>
 
  <para>
-  The <filename>xml2</> module provides XPath querying and
+  The <filename>xml2</filename> module provides XPath querying and
   XSLT functionality.
  </para>
 
@@ -16,7 +16,7 @@
   <title>Deprecation Notice</title>
 
   <para>
-   From <productname>PostgreSQL</> 8.3 on, there is XML-related
+   From <productname>PostgreSQL</productname> 8.3 on, there is XML-related
    functionality based on the SQL/XML standard in the core server.
    That functionality covers XML syntax checking and XPath queries,
    which is what this module does, and more, but the API is
@@ -36,7 +36,7 @@
   <para>
    <xref linkend="xml2-functions-table"> shows the functions provided by this module.
    These functions provide straightforward XML parsing and XPath queries.
-   All arguments are of type <type>text</>, so for brevity that is not shown.
+   All arguments are of type <type>text</type>, so for brevity that is not shown.
   </para>
 
   <table id="xml2-functions-table">
@@ -63,8 +63,8 @@
        <para>
         This parses the document text in its parameter and returns true if the
         document is well-formed XML.  (Note: this is an alias for the standard
-        PostgreSQL function <function>xml_is_well_formed()</>.  The
-        name <function>xml_valid()</> is technically incorrect since validity
+        PostgreSQL function <function>xml_is_well_formed()</function>.  The
+        name <function>xml_valid()</function> is technically incorrect since validity
         and well-formedness have different meanings in XML.)
        </para>
       </entry>
@@ -124,7 +124,7 @@
 &lt;itemtag&gt;Value 2....&lt;/itemtag&gt;
 &lt;/toptag&gt;
 </synopsis>
-        If either <literal>toptag</> or <literal>itemtag</> is an empty string, the relevant tag is omitted.
+        If either <literal>toptag</literal> or <literal>itemtag</literal> is an empty string, the relevant tag is omitted.
        </para>
       </entry>
      </row>
@@ -139,7 +139,7 @@
       </entry>
       <entry>
        <para>
-        Like <function>xpath_nodeset(document, query, toptag, itemtag)</> but result omits both tags.
+        Like <function>xpath_nodeset(document, query, toptag, itemtag)</function> but result omits both tags.
        </para>
       </entry>
      </row>
@@ -154,7 +154,7 @@
       </entry>
       <entry>
        <para>
-        Like <function>xpath_nodeset(document, query, toptag, itemtag)</> but result omits <literal>toptag</literal>.
+        Like <function>xpath_nodeset(document, query, toptag, itemtag)</function> but result omits <literal>toptag</literal>.
        </para>
       </entry>
      </row>
@@ -170,8 +170,8 @@
       <entry>
        <para>
         This function returns multiple values separated by the specified
-        separator, for example <literal>Value 1,Value 2,Value 3</> if
-        separator is <literal>,</>.
+        separator, for example <literal>Value 1,Value 2,Value 3</literal> if
+        separator is <literal>,</literal>.
        </para>
       </entry>
      </row>
@@ -185,7 +185,7 @@
        <type>text</type>
       </entry>
       <entry>
-       This is a wrapper for the above function that uses <literal>,</>
+       This is a wrapper for the above function that uses <literal>,</literal>
        as the separator.
       </entry>
      </row>
@@ -206,7 +206,7 @@ xpath_table(text key, text document, text relation, text xpaths, text criteria)
 </synopsis>
 
   <para>
-   <function>xpath_table</> is a table function that evaluates a set of XPath
+   <function>xpath_table</function> is a table function that evaluates a set of XPath
    queries on each of a set of documents and returns the results as a
    table. The primary key field from the original document table is returned
    as the first column of the result so that the result set
@@ -228,7 +228,7 @@ xpath_table(text key, text document, text relation, text xpaths, text criteria)
       <entry><parameter>key</parameter></entry>
       <entry>
        <para>
-        the name of the <quote>key</> field &mdash; this is just a field to be used as
+        the name of the <quote>key</quote> field &mdash; this is just a field to be used as
         the first column of the output table, i.e., it identifies the record from
         which each output row came (see note below about multiple values)
        </para>
@@ -285,7 +285,7 @@ xpath_table(text key, text document, text relation, text xpaths, text criteria)
   </para>
 
   <para>
-   so those parameters can be <emphasis>anything</> valid in those particular
+   so those parameters can be <emphasis>anything</emphasis> valid in those particular
    locations. The result from this SELECT needs to return exactly two
    columns (which it will unless you try to list multiple fields for key
    or document). Beware that this simplistic approach requires that you
@@ -293,8 +293,8 @@ xpath_table(text key, text document, text relation, text xpaths, text criteria)
   </para>
 
   <para>
-   The function has to be used in a <literal>FROM</> expression, with an
-   <literal>AS</> clause to specify the output columns; for example
+   The function has to be used in a <literal>FROM</literal> expression, with an
+   <literal>AS</literal> clause to specify the output columns; for example
 <programlisting>
 SELECT * FROM
 xpath_table('article_id',
@@ -304,8 +304,8 @@ xpath_table('article_id',
             'date_entered > ''2003-01-01'' ')
 AS t(article_id integer, author text, page_count integer, title text);
 </programlisting>
-   The <literal>AS</> clause defines the names and types of the columns in the
-   output table.  The first is the <quote>key</> field and the rest correspond
+   The <literal>AS</literal> clause defines the names and types of the columns in the
+   output table.  The first is the <quote>key</quote> field and the rest correspond
    to the XPath queries.
    If there are more XPath queries than result columns,
    the extra queries will be ignored. If there are more result columns
@@ -313,19 +313,19 @@ AS t(article_id integer, author text, page_count integer, title text);
   </para>
 
   <para>
-   Notice that this example defines the <structname>page_count</> result
+   Notice that this example defines the <structname>page_count</structname> result
    column as an integer.  The function deals internally with string
    representations, so when you say you want an integer in the output, it will
    take the string representation of the XPath result and use PostgreSQL input
-   functions to transform it into an integer (or whatever type the <type>AS</>
+   functions to transform it into an integer (or whatever type the <type>AS</type>
    clause requests). An error will result if it can't do this &mdash; for
    example if the result is empty &mdash; so you may wish to just stick to
-   <type>text</> as the column type if you think your data has any problems.
+   <type>text</type> as the column type if you think your data has any problems.
   </para>
 
   <para>
-   The calling <command>SELECT</> statement doesn't necessarily have to be
-   just <literal>SELECT *</> &mdash; it can reference the output
+   The calling <command>SELECT</command> statement doesn't necessarily have to be
+   just <literal>SELECT *</literal> &mdash; it can reference the output
    columns by name or join them to other tables. The function produces a
    virtual table with which you can perform any operation you wish (e.g.
    aggregation, joining, sorting etc). So we could also have:
@@ -346,7 +346,7 @@ WHERE t.author_id = p.person_id;
    <title>Multivalued Results</title>
 
    <para>
-    The <function>xpath_table</> function assumes that the results of each XPath query
+    The <function>xpath_table</function> function assumes that the results of each XPath query
     might be multivalued, so the number of rows returned by the function
     may not be the same as the number of input documents. The first row
     returned contains the first result from each query, the second row the
@@ -393,8 +393,8 @@ WHERE id = 1 ORDER BY doc_num, line_num
    </para>
 
    <para>
-    To get <literal>doc_num</> on every line, the solution is to use two invocations
-    of <function>xpath_table</> and join the results:
+    To get <literal>doc_num</literal> on every line, the solution is to use two invocations
+    of <function>xpath_table</function> and join the results:
 
 <programlisting>
 SELECT t.*,i.doc_num FROM
@@ -437,15 +437,15 @@ xslt_process(text document, text stylesheet, text paramlist) returns text
 
    <para>
     This function applies the XSL stylesheet to the document and returns
-    the transformed result. The <literal>paramlist</> is a list of parameter
+    the transformed result. The <literal>paramlist</literal> is a list of parameter
     assignments to be used in the transformation, specified in the form
-    <literal>a=1,b=2</>. Note that the
+    <literal>a=1,b=2</literal>. Note that the
     parameter parsing is very simple-minded: parameter values cannot
     contain commas!
    </para>
 
    <para>
-    There is also a two-parameter version of <function>xslt_process</> which
+    There is also a two-parameter version of <function>xslt_process</function> which
     does not pass any parameters to the transformation.
    </para>
   </sect3>