Insert proper xmlns attributes.

Running the test suite with this version ("./runtest.sh -c") now shows
two failures:

- test2: the checked-in test output is missing the xmlns="..."
  attributes because the Printer module doesn't emit these for
  prefix-less xmlns attributes (in cases where node.namespaceURI is
  set but node.prefix is None).

- test8: this version emits a redundant xmlns:m attribute on the
  expanded macro element.  AFAICT this is OK according to the XMLNS
  standard.  The redundant attribute is emitted because macros are
  compiled without context (since they may be used in a different
  context).

lib/python/TAL/TALCompiler.py

@@ -86,8 +86,7 @@
 Compile a DOM tree for efficient TAL expansion.
 
 XXX TO DO:
-- xmlns attributes
-- get macro use/define substitution right
+- get macro use/define substitution right (currently ignores prefix)
 """
 
 import string
@@ -110,6 +109,8 @@ class TALCompiler(DOMVisitor):
         self.macros = {}
         self.program = []
         self.stack = []
+        self.namespaceDict = {}
+        self.namespaceStack = [self.namespaceDict]
         DOMVisitor.__call__(self)
         assert not self.stack
         return self.program, self.macros
@@ -123,22 +124,57 @@ class TALCompiler(DOMVisitor):
         self.program = self.stack.pop()
         return program
 
+    def pushNS(self):
+        self.namespaceStack.append(self.namespaceDict)
+
+    def popNS(self):
+        self.namespaceDict = self.namespaceStack.pop()
+
+    def newNS(self, prefix, namespaceURI):
+        if self.namespaceDict is self.namespaceStack[-1]:
+            self.namespaceDict = self.namespaceDict.copy()
+        if self.namespaceDict.get(prefix) != namespaceURI:
+            self.namespaceDict[prefix] = namespaceURI
+            return 1
+        else:
+            return 0
+
+    def getFullAttrList(self, node):
+        list = []
+        if node.namespaceURI:
+            if self.newNS(node.prefix, node.namespaceURI):
+                if node.prefix:
+                    list.append(("xmlns:" + node.prefix, node.namespaceURI))
+                else:
+                    list.append(("xmlns", node.namespaceURI))
+        for attr in node.attributes.values():
+            if attr.namespaceURI:
+                if self.newNS(attr.prefix, attr.namespaceURI):
+                    list.append(("xmlns:" + attr.prefix, attr.namespaceURI))
+        list.extend(getAttributeList(node))
+        return list
+
     def emit(self, *instruction):
         self.program.append(instruction)
 
     def emitStartTag(self, node):
-        self.emit("startTag", node.nodeName, getAttributeList(node))
+        self.emit("startTag", node.nodeName, self.getFullAttrList(node))
 
     def emitStartEndTag(self, node):
-        self.emit("startEndTag", node.nodeName, getAttributeList(node))
+        self.emit("startEndTag", node.nodeName, self.getFullAttrList(node))
 
     def emitEndTag(self, node):
         self.emit("endTag", node.nodeName)
 
     def visitElement(self, node):
+        self.pushNS()
         if not node.hasAttributes():
             self.emitElement(node)
-            return
+        else:
+            self.expandElement(node)
+        self.popNS()
+
+    def expandElement(self, node):
         macroName = node.getAttributeNS(ZOPE_METAL_NS, "use-macro")
         if macroName:
             slotDict = slotIndexer(node)