try to fix a problem with valgrind. applied memory leak fix from Brent

* Makefile.am doc/examples/Makefile.am python/tests/Makefile.am
  xstc/Makefile.am: try to fix a problem with valgrind.
* python/generator.py python/libxml.c python/tests/Makefile.am
  python/tests/tstmem.py: applied memory leak fix from Brent Hendricks
  c.f. bug #165349
Daniel

python/generator.py

@@ -344,6 +344,8 @@ def skip_function(name):
     # the next function is defined in libxml.c
     if name == "xmlRelaxNGFreeValidCtxt":
         return 1
+    if name == "xmlFreeValidCtxt":
+        return 1
 #
 # Those are skipped because the Const version is used of the bindings
 # instead.

python/libxml.c

@@ -1858,6 +1858,31 @@ libxml_xmlSetValidErrors(ATTRIBUTE_UNUSED PyObject * self, PyObject * args)
     return (py_retval);
 }
 
+
+PyObject *
+libxml_xmlFreeValidCtxt(PyObject *self ATTRIBUTE_UNUSED, PyObject *args) {
+    xmlValidCtxtPtr cur;
+    xmlValidCtxtPyCtxtPtr pyCtxt;
+    PyObject *pyobj_cur;
+
+    if (!PyArg_ParseTuple(args, (char *)"O:xmlFreeValidCtxt", &pyobj_cur))
+        return(NULL);
+    cur = (xmlValidCtxtPtr) PyValidCtxt_Get(pyobj_cur);
+
+    pyCtxt = (xmlValidCtxtPyCtxtPtr)(cur->userData);
+    if (pyCtxt != NULL)
+    {
+            Py_XDECREF(pyCtxt->error);
+            Py_XDECREF(pyCtxt->warn);
+            Py_XDECREF(pyCtxt->arg);
+            xmlFree(pyCtxt);
+    }
+
+    xmlFreeValidCtxt(cur);
+    Py_INCREF(Py_None);
+    return(Py_None);
+}
+
 /************************************************************************
  *									*
  *                      Per xmlTextReader error handler                 *
@@ -3618,6 +3643,7 @@ static PyMethodDef libxmlMethods[] = {
     {(char *) "doc", libxml_doc, METH_VARARGS, NULL},
     {(char *) "xmlNewNode", libxml_xmlNewNode, METH_VARARGS, NULL},
     {(char *)"xmlSetValidErrors", libxml_xmlSetValidErrors, METH_VARARGS, NULL},
+    {(char *)"xmlFreeValidCtxt", libxml_xmlFreeValidCtxt, METH_VARARGS, NULL},
 #ifdef LIBXML_OUTPUT_ENABLED
     {(char *) "serializeNode", libxml_serializeNode, METH_VARARGS, NULL},
     {(char *) "saveNodeTo", libxml_saveNodeTo, METH_VARARGS, NULL},

python/tests/Makefile.am

@@ -37,7 +37,8 @@ PYTESTS=	\
     sync.py \
     tstLastError.py \
     indexes.py \
-    dtdvalid.py
+    dtdvalid.py \
+    tstmem.py
 
 XMLS=		\
     tst.xml	\

python/tests/tstmem.py

@@ -0,0 +1,36 @@
+#!/usr/bin/python -u
+import libxml2
+import libxml2mod
+import sys
+
+def error(msg, data):
+    pass
+
+# Memory debug specific
+libxml2.debugMemory(1)
+
+dtd="""<!ELEMENT foo EMPTY>"""
+instance="""<?xml version="1.0"?>
+<foo></foo>"""
+
+dtd = libxml2.parseDTD(None, 'test.dtd')
+ctxt = libxml2.newValidCtxt()
+libxml2mod.xmlSetValidErrors(ctxt._o, error, error)
+doc = libxml2.parseDoc(instance)
+ret = doc.validateDtd(ctxt, dtd)
+if ret != 1:
+    print "error doing DTD validation"
+    sys.exit(1)
+
+doc.freeDoc()
+dtd.freeDtd()
+del dtd
+del ctxt
+
+# Memory debug specific
+libxml2.cleanupParser()
+if libxml2.debugMemory(1) == 0:
+    print "OK"
+else:
+    print "Memory leak %d bytes" % (libxml2.debugMemory(1))
+    libxml2.dumpMemory()