Update the test suite to cover more ground.

This closes patch #102477.

Lib/test/output/test_minidom

@@ -127,6 +127,7 @@ Test Succeeded testNonZero
 Passed assertion: len(Node.allnodes) == 0
 Passed testNormalize -- preparation
 Passed testNormalize -- result
+Passed testNormalize -- single empty node removed
 Test Succeeded testNormalize
 Passed assertion: len(Node.allnodes) == 0
 Passed testParents

Lib/test/test_minidom.py

@@ -397,6 +397,14 @@ def testNormalize():
             , "testNormalize -- result")
     doc.unlink()
 
+    doc = parseString("<doc/>")
+    root = doc.documentElement
+    root.appendChild(doc.createTextNode(""))
+    doc.normalize()
+    confirm(len(root.childNodes) == 0,
+            "testNormalize -- single empty node removed")
+    doc.unlink()
+
 def testSiblings():
     doc = parseString("<doc><?pi?>text?<elm/></doc>")
     root = doc.documentElement