Added function xml.sax.saxutils.quoteattr().

This closes SF bug #440351.  It should not be moved to Python 2.1.1.

Lib/xml/sax/saxutils.py

@@ -27,6 +27,27 @@ def escape(data, entities={}):
         data = data.replace(chars, entity)
     return data
 
+def quoteattr(data, entities={}):
+    """Escape and quote an attribute value.
+
+    Escape &, <, and > in a string of data, then quote it for use as
+    an attribute value.  The \" character will be escaped as well, if
+    necessary.
+
+    You can escape other strings of data by passing a dictionary as
+    the optional entities parameter.  The keys and values must all be
+    strings; each key will be replaced with its corresponding value.
+    """
+    data = escape(data, entities)
+    if '"' in data:
+        if "'" in data:
+            data = '"%s"' % data.replace('"', "&quot;")
+        else:
+            data = "'%s'" % data
+    else:
+        data = '"%s"' % data
+    return data
+
 
 class XMLGenerator(handler.ContentHandler):