fixed bug #132575 about finding the end of the internal subset in push

* parser.c: fixed bug #132575 about finding the end of the
  internal subset in push mode.
* test/intsubset.xml result/intsubset.xml* result/noent/intsubset.xml:
  added the test to the regression suite
Daniel
diff --git a/result/intsubset.xml.sax b/result/intsubset.xml.sax
new file mode 100644
index 0000000..a92e2b7
--- /dev/null
+++ b/result/intsubset.xml.sax
@@ -0,0 +1,9 @@
+SAX.setDocumentLocator()
+SAX.startDocument()
+SAX.internalSubset(root, , )
+SAX.elementDecl(root, 1, ...)
+SAX.comment(  " )
+SAX.externalSubset(root, , )
+SAX.startElement(root)
+SAX.endElement(root)
+SAX.endDocument()