Because msgstore_fs writes logs in localtime, the CHATHISTORY timestamps
(UTC) must be converted to localtime prior to filtering ranges ensure
the right range is sent back to the client.
Prior to this patch, the iteration back from the BEFORE time failed to
load the hours between midnight UTC and midnight localtime in each day's
logged messages. This is because the final time to be considered in a
day's log file (the "start" time) reuses the previous start time's
locale:
start = time.Date(year, month, day, 0, 0, 0, 0, start.Location()).Add(-1)
By converting the original start and end from the CHATHISTORY commands
to localtime in Load*Time and ListTargets, we ensure we read through
midnight each day.
This allows to have shorter and more future-proof IDs. This also
guarantees the IDs will only use reasonable ASCII characters (no
spaces), removing the need to encode them for PING/PONG tokens.
