Added code submitted by Andreas Pakulat to provide node equality,

* python/libxml.c, python/libxml.py, python/tests/compareNodes.py,
  python/tests/Makefile.am:
  Added code submitted by Andreas Pakulat to provide node
  equality, inequality and hash functions, plus a single
  test program to check the functions (bugs 345779 + 345961).

python/tests/Makefile.am

@@ -43,7 +43,8 @@ PYTESTS=	\
     tstmem.py	\
     validDTD.py	\
     validSchemas.py \
-    validRNG.py
+    validRNG.py \
+    compareNodes.py
 
 XMLS=		\
     tst.xml	\

python/tests/compareNodes.py

@@ -0,0 +1,50 @@
+#!/usr/bin/python -u
+import sys
+import libxml2
+
+# Memory debug specific
+libxml2.debugMemory(1)
+
+#
+# Testing XML Node comparison and Node hash-value
+#
+doc = libxml2.parseDoc("""<root><foo/></root>""")
+root = doc.getRootElement()
+
+# Create two different objects which point to foo
+foonode1 = root.children
+foonode2 = root.children
+
+# Now check that [in]equality tests work ok
+if not ( foonode1 == foonode2 ):
+    print "Error comparing nodes with ==, nodes should be equal but are unequal"
+    sys.exit(1)
+if not ( foonode1 != root ):
+    print "Error comparing nodes with ==, nodes should not be equal but are equal"
+    sys.exit(1)
+if not ( foonode1 != root ):
+    print "Error comparing nodes with !=, nodes should not be equal but are equal"
+if ( foonode1 != foonode2 ):
+    print "Error comparing nodes with !=, nodes should be equal but are unequal"
+
+# Next check that the hash function for the objects also works ok
+if not (hash(foonode1) == hash(foonode2)):
+    print "Error hash values for two equal nodes are different"
+    sys.exit(1)
+if not (hash(foonode1) != hash(root)):
+    print "Error hash values for two unequal nodes are not different"
+    sys.exit(1)
+if hash(foonode1) == hash(root):
+    print "Error hash values for two unequal nodes are equal"
+    sys.exit(1)
+
+# Basic tests successful
+doc.freeDoc()
+
+# Memory debug specific
+libxml2.cleanupParser()
+if libxml2.debugMemory(1) == 0:
+    print "OK"
+else:
+    print "Memory leak %d bytes" % (libxml2.debugMemory(1))
+    libxml2.dumpMemory()