# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1421948466 -3600
# Node ID 6a4c7cc21fbb5ec6b65dafa90a9e2c6a0e372794
# Parent  bb9494547de1d617bf1bdc10542e1e9d613d5020
Made a separate function for testing if objects are new, making use of PARTSTAT
for objects prepared by apparently non-compliant calendar clients.

diff -r bb9494547de1 -r 6a4c7cc21fbb imiptools/content.py
--- a/imiptools/content.py	Thu Jan 22 17:50:54 2015 +0100
+++ b/imiptools/content.py	Thu Jan 22 18:41:06 2015 +0100
@@ -107,6 +107,28 @@
 def uri_items(items):
     return [(get_uri(value), attr) for value, attr in items]
 
+def is_new_object(old_sequence, new_sequence, old_dtstamp, new_dtstamp, partstat_set):
+
+    """
+    Return for the given 'old_sequence' and 'new_sequence', 'old_dtstamp' and
+    'new_dtstamp', and the 'partstat_set' indication, whether the object
+    providing the new information is really newer than the object providing the
+    old information.
+    """
+
+    have_sequence = old_sequence is not None and new_sequence is not None
+    is_same_sequence = have_sequence and int(new_sequence) == int(old_sequence)
+
+    have_dtstamp = old_dtstamp and new_dtstamp
+    is_old_dtstamp = have_dtstamp and new_dtstamp < old_dtstamp or old_dtstamp and not new_dtstamp
+
+    is_old_sequence = have_sequence and (
+        int(new_sequence) < int(old_sequence) or
+        is_same_sequence and is_old_dtstamp
+        )
+
+    return is_same_sequence and partstat_set or not is_old_sequence
+
 # NOTE: Need to expose the 100 day window for recurring events in the
 # NOTE: configuration.
 
@@ -426,19 +448,22 @@
             sequence = get_value(obj, "SEQUENCE")
             dtstamp = get_value(obj, "DTSTAMP")
 
+            # NOTE: Some clients like Claws Mail erase time information from DTSTAMP
+            # NOTE: and make it invalid. Thus, attendance information may also be
+            # NOTE: checked.
+
+            _attendee, old_attr = get_item(obj, "ATTENDEE")
+            _attendee, new_attr = self.get_item("ATTENDEE")
+            old_partstat = old_attr.get("PARTSTAT")
+            new_partstat = new_attr.get("PARTSTAT")
+
+            partstat_set = old_partstat == "NEEDS-ACTION" and new_partstat and \
+                new_partstat != old_partstat
+
             # If the request refers to an older version of the object, ignore
             # it.
 
-            old_dtstamp = self.dtstamp < dtstamp
-
-            have_sequence = sequence is not None and self.sequence is not None
-
-            if have_sequence and (
-                int(self.sequence) < int(sequence) or
-                int(self.sequence) == int(sequence) and old_dtstamp
-                ) or not have_sequence and old_dtstamp:
-
-                return False
+            return is_new_object(sequence, self.sequence, dtstamp, self.dtstamp, partstat_set)
 
         return True