Index: Lib/xml/dom/minidom.py
===================================================================
--- Lib/xml/dom/minidom.py	(revision 61002)
+++ Lib/xml/dom/minidom.py	(working copy)
@@ -20,6 +20,8 @@
 from xml.dom.minicompat import *
 from xml.dom.xmlbuilder import DOMImplementationLS, DocumentLS
 
+import itertools
+
 # This is used by the ID-cache invalidation checks; the list isn't
 # actually complete, since the nodes being checked will never be the
 # DOCUMENT_NODE or DOCUMENT_FRAGMENT_NODE.  (The node being checked is
@@ -174,37 +176,32 @@
         return oldChild
 
     def normalize(self):
+        # Pass 1: Discard empty text nodes, collapse adjacent text nodes.
         L = []
         for child in self.childNodes:
             if child.nodeType == Node.TEXT_NODE:
                 data = child.data
-                if data and L and L[-1].nodeType == child.nodeType:
-                    # collapse text node
-                    node = L[-1]
-                    node.data = node.data + child.data
-                    node.nextSibling = child.nextSibling
+                if not data:
+                    # Discard empty text node.
                     child.unlink()
-                elif data:
-                    if L:
-                        L[-1].nextSibling = child
-                        child.previousSibling = L[-1]
-                    else:
-                        child.previousSibling = None
-                    L.append(child)
-                else:
-                    # empty text node; discard
+                elif L and L[-1].nodeType == Node.TEXT_NODE:
+                    # Collapse adjacent text nodes.
+                    L[-1].data += data
                     child.unlink()
-            else:
-                if L:
-                    L[-1].nextSibling = child
-                    child.previousSibling = L[-1]
                 else:
-                    child.previousSibling = None
+                    L.append(child)
+            else:
                 L.append(child)
                 if child.nodeType == Node.ELEMENT_NODE:
                     child.normalize()
-        if L:
-            L[-1].nextSibling = None
+
+        # Pass 2: Recreate the previous/next links.
+        previous_L = itertools.chain([None], L)
+        next_L = itertools.chain(itertools.islice(L, 1, None), [None])
+        for prev, child, next in itertools.izip(previous_L, L, next_L):
+            child.previousSibling = prev
+            child.nextSibling = next
+
         self.childNodes[:] = L
 
     def cloneNode(self, deep):