--last does not respect multiple events on a package

[herzrasen]

When querying using --last n it is ignored when multiple events occurred on a single package.

For exampe i3-gaps has been installed and removed multiple times which is using to many "slots" in the result set.

[2019-08-25 20:52] [ALPM] installed yajl (2.1.0-2)
[2019-08-25 20:52] [ALPM] installed i3-gaps (4.17-1)
[2019-08-25 20:52] [ALPM] installed i3blocks (1.4-6)
[2019-08-25 20:52] [ALPM] installed i3lock (2.12-1)
[2019-08-25 20:52] [ALPM] installed confuse (3.2.2-1)
[2019-08-25 20:52] [ALPM] installed i3status (2.13-2)
[2019-08-25 20:52] [ALPM] transaction completed
[2019-08-25 20:52] [ALPM] running 'systemd-update.hook'...
[2019-08-25 20:52] [ALPM] running 'update-desktop-database.hook'...
[2019-08-25 21:32] [ALPM] transaction started
[2019-08-25 21:32] [ALPM] removed i3status (2.13-2)
[2019-08-25 21:32] [ALPM] removed i3lock (2.12-1)
[2019-08-25 21:32] [ALPM] removed i3blocks (1.4-6)
[2019-08-25 21:32] [ALPM] removed i3-gaps (4.17-1)
[2019-08-25 21:32] [ALPM] transaction completed
[2019-08-25 21:32] [ALPM] running 'systemd-update.hook'...
[2019-08-25 21:32] [ALPM] running 'update-desktop-database.hook'...
[2019-08-25 21:33] [ALPM] transaction started
[2019-08-25 21:33] [ALPM] upgraded libldap (2.4.47-3 -> 2.4.48-1)
[2019-08-25 21:33] [ALPM] upgraded llvm-libs (8.0.1-2 -> 8.0.1-3)
[2019-08-25 21:33] [ALPM] transaction completed
[2019-08-25 21:33] [ALPM] running 'systemd-update.hook'...
[2019-08-26 13:39] [ALPM] transaction started
[2019-08-26 13:39] [ALPM] reinstalled st (0.8.2-2)
[2019-08-26 13:39] [ALPM] transaction completed
[2019-08-26 13:39] [ALPM] running 'systemd-update.hook'...
[2019-08-26 14:13] [ALPM] transaction started
[2019-08-26 14:13] [ALPM] installed i3-gaps (4.17-1)
[2019-08-26 14:13] [ALPM] installed i3lock (2.12-1)
[2019-08-26 14:13] [ALPM] transaction completed
[2019-08-26 14:13] [ALPM] running 'systemd-update.hook'...
[2019-08-26 14:13] [ALPM] running 'update-desktop-database.hook'...
[2019-08-26 14:17] [ALPM] transaction started
[2019-08-26 14:17] [ALPM] installed herbstluftwm (0.7.2-1)
[2019-08-26 14:17] [ALPM] transaction completed
[2019-08-26 14:17] [ALPM] running 'systemd-update.hook'...
[2019-08-26 14:17] [ALPM] transaction started
[2019-08-26 14:17] [ALPM] installed dzen2 (0.9.5.14.488ab66-1)
[2019-08-26 14:17] [ALPM] transaction completed
[2019-08-26 14:17] [ALPM] running 'systemd-update.hook'...
[2019-08-26 14:29] [ALPM] transaction started
[2019-08-26 14:29] [ALPM] removed dzen2 (0.9.5.14.488ab66-1)
[2019-08-26 14:29] [ALPM] removed herbstluftwm (0.7.2-1)

╰─➤  pkghist --last 20 --limit 1
confuse
  [2019-08-25 20:52:00] Installed
    3.2.2-1
yajl
  [2019-08-25 20:52:00] Installed
    2.1.0-2
libldap
  [2019-08-25 21:33:00] Upgraded
    2.4.48-1
llvm-libs
  [2019-08-25 21:33:00] Upgraded
    8.0.1-3
i3-gaps
  [2019-08-26 14:13:00] Installed
    4.17-1
i3lock
  [2019-08-26 14:13:00] Installed
    2.12-1