394         prevrev = store.parentrevs(revs[0])[0]

   394         prevrev = store.parentrevs(revs[0])[0]

   395 

   395 

   396     # Set of revs available to delta against.

   396     # Set of revs available to delta against.

   397     available = set()

   397     available = set()

   398 

   398 

   399     for rev in revs:

   402     for rev in revs:

   400         if rev == nullrev:

   403         if rev == nullrev:

   401             continue

   404             continue

   402 

   405 

   403         debug_delta_source = None

   406         debug_delta_source = None

   443         # amounts to effectively copying data from storage and is

   446         # amounts to effectively copying data from storage and is

   444         # therefore the fastest.

   447         # therefore the fastest.

   445         elif deltaparentrev != nullrev:

   448         elif deltaparentrev != nullrev:

   446             # Base revision was already emitted in this group. We can

   449             # Base revision was already emitted in this group. We can

   447             # always safely use the delta.

   450             # always safely use the delta.

   449                 if debug_info is not None:

   452                 if debug_info is not None:

   450                     debug_delta_source = "storage"

   453                     debug_delta_source = "storage"

   451                 baserev = deltaparentrev

   454                 baserev = deltaparentrev

   452 

   455 

   453             # Base revision is a parent that hasn't been emitted already.

   456             # Base revision is a parent that hasn't been emitted already.