Handle cite attribute

mbox2web

@@ -469,12 +469,15 @@ class HTMLPart(html.parser.HTMLParser):
             if href:
                 self.base = href[0]
         elif tag in self.allowed_tags:
+            cleaned_attrs, extra = self.clean_attrs(tag, attrs)
             attrstr = "".join(
                             [' %s="%s"' % (a[0],  html.escape(a[1])) if a[1] else ' %s' % (a[0])
-                                for a in self.clean_attrs(tag, attrs)
+                                for a in cleaned_attrs
                             ]
                          )
             self.content.append("<%s%s>" % ( tag, attrstr ))
+            if extra:
+                self.content.append(extra)
         elif tag in self.hide_tags:
             self.hide = True
         elif tag in self.ignore_tags:
@@ -507,6 +510,7 @@ class HTMLPart(html.parser.HTMLParser):
             "noshade", "type",
         ]
         clean_attrs = []
+        extra = None
         for a in attrs:
             if a[0] in safe_attrs:
                 clean_attrs.append(a)
@@ -527,9 +531,14 @@ class HTMLPart(html.parser.HTMLParser):
                     print("Ignored src attribute", a, file=sys.stderr)
             elif a[0] == "target":
                 pass
+            elif a[0] == "cite":
+                if a[1].startswith("mid:"):
+                    mid = a[1][4:]
+                    encmid = encode_message_id(mid)
+                    extra = "<a class='citesource' href='../%s'>\u2397</a>" % encmid
             else:
                 print("Encountered unknown attribute", a, file=sys.stderr)
-        return clean_attrs
+        return clean_attrs, extra
 
 
 class TextEnrichedPart: