.

wcfs/wcfs_test.py

@@ -895,6 +895,7 @@ def watch(twlink, zf, at, pinok=None): # -> tWatch
                 assert False, '#%d pinned %s; not pinned %s' % (t.hat(at_prev), t.hat(at))
 
             # blk ∈ pin     -> blk was already accessed with rev > at
+            # (see criteria in _pinnedAt)
             assert blk in headOfAccess
             assert at  <  blkRevAt(blk, headOfAccess[blk])
 
@@ -1138,7 +1139,8 @@ def _pinnedAt(t, zf, at):  # -> pin = {} blk -> rev
             else:
                 pinrev = blkhistoryat[-1]
             assert pinrev <= at
-            pin[blk] = pinrev   # XXX headOfAccess >= ...
+            if t._headOfAccess(zf).get(blk, z64) >= at:
+                pin[blk] = pinrev
 
     return pin