fixed nextCatalog started adding a small regression test Daniel

* catalog.c: fixed nextCatalog
* result/catalogs/docbook test/catalogs/*: started adding
  a small regression test
Daniel
diff --git a/test/catalogs/docbook.xml b/test/catalogs/docbook.xml
new file mode 100644
index 0000000..c8dd2bf
--- /dev/null
+++ b/test/catalogs/docbook.xml
@@ -0,0 +1,14 @@
+<?xml version="1.0"?>
+<!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN" "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd">
+<catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog">
+<public publicId="-//OASIS//DTD DocBook XML V4.1.2//EN" uri="http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"/>
+<public publicId="-//OASIS//ENTITIES DocBook XML Notations V4.1.2//EN" uri="http://www.oasis-open.org/docbook/xml/4.1.2/dbnotnx.mod"/>
+<public publicId="-//OASIS//ENTITIES DocBook XML Character Entities V4.1.2//EN" uri="http://www.oasis-open.org/docbook/xml/4.1.2/dbcentx.mod"/>
+<public publicId="-//OASIS//ELEMENTS DocBook XML Information Pool V4.1.2//EN" uri="http://www.oasis-open.org/docbook/xml/4.1.2/dbpoolx.mod"/>
+<public publicId="-//OASIS//ELEMENTS DocBook XML Document Hierarchy V4.1.2//EN" uri="http://www.oasis-open.org/docbook/xml/4.1.2/dbhierx.mod"/>
+<public publicId="-//OASIS//ENTITIES DocBook XML Additional General Entities V4.1.2//EN" uri="http://www.oasis-open.org/docbook/xml/4.1.2/dbgenent.mod"/>
+<public publicId="-//OASIS//DTD DocBook XML CALS Table Model V4.1.2//EN" uri="http://www.oasis-open.org/docbook/xml/4.1.2/calstblx.dtd"/>
+<public publicId="-//OASIS//DTD DocBook MathML Module V1.0//EN" uri="http://www.oasis-open.org/docbook/xml/mathml/1.0/dbmathml.dtd"/>
+<nextCatalog catalog="stylesheet.xml"/>
+<rewriteSystem systemIdStartString="http://www.oasis-open.org/docbook/" rewritePrefix="/usr/share/xml/docbook/"/>
+</catalog>