Fix LRU blue moon bug in RESTORE, RDB loading, module API (#9279)

The `lru_clock` and `lru` bits in `robj` save the least significant 24 bits of the unixtime (seconds since 1/1/1970),
and wrap around every 194 days.
The `objectSetLRUOrLFU` function, which is used in RESTORE with IDLETIME argument, and also in replica
or master loading an RDB that contains LRU, and by a module API had a bug that's triggered when that happens.

The scenario was that the idle time that came from the user, let's say RESTORE command is about 1000 seconds
(e.g. in the `RESTORE can set LRU` test we have), and the current `lru_clock` just wrapped around and is less than
1000 (i.e. a period of 1000 seconds once in some 6 months), the expression in that function would produce a negative
value and the code (and comment) specified that the best way to solve that is push the idle time backwards into the
past by 3 months. i.e. an idle time of 3 months instead of 1000 seconds.

instead, the right thing to do is to unwrap it, and put it near LRU_CLOCK_MAX. since now `lru_clock` is smaller than
`obj->lru` it will be unwrapped again by `estimateObjectIdleTime`.

bug was introduced by 052e03495f, but the code before it also seemed wrong.

0 files changed, 0 insertions, 0 deletions