[dovecot/core] 06ff86: lib-storage: Fix sorting mails with the same prima...

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/dovecot/core
  Commit: 06ff86fc92a789e9239dccbb4300f7994ee8842e
      https://github.com/dovecot/core/commit/06ff86fc92a789e9239dccbb4300f7994ee8842e
  Author: Timo Sirainen <timo.sirainen at dovecot.fi>
  Date:   2017-11-24 (Fri, 24 Nov 2017)

  Changed paths:
    M src/lib-storage/index/index-sort-string.c

  Log Message:
  -----------
  lib-storage: Fix sorting mails with the same primary sort key

The sorting order may have been wrong when there was a combination of:
 * Messages were sorted by a string (e.g. Subject)
 * Some messages had the same sort key (e.g. same base subject)
 * Within the messages with the same sort key, some of the messages already
   had the "sort-*" index number in Dovecot indexes, but some of them
   didn't.

The result was that Dovecot found that the two messages had exactly the same
sort key. It should have continued with the secondary sort key (e.g.
message sequence number), but it didn't.