Fixed "Evolution doesn't happen with initial day set at 30 #33450"

[ipcyborg]

Summary

SUMMARY: Bugfixes "Evolution doesn't happen with initial day set at 30 #33450"

Purpose of change

Fixes #33450

Describe the solution

Fixed logical error: upgrade_time is in days, not in turns.
When initial_day is set, it affects start_of_cataclysm. Then ``start_of_cataclysmis added toupgrade_time` in turns, which is a bug number for 30 days. So the evolution was really postponed.

Also removed time_point to time_point cast. Or is it required somehow?

Tested for initial_day=30, spawn delay=999. Observed a Kevlar hulk and other evolved monsters immediately.

Describe alternatives you've considered

None

Additional context

I think this PR needs extensive testing.

[ipcyborg]

The build continuous-integration/travis-ci/pr failed, but I can't find the reason for it in the log.
Is it possible to re-do this check?

[BevapDin]

Error can be seen at https://travis-ci.org/CleverRaven/Cataclysm-DDA/jobs/575868273

/home/travis/build/CleverRaven/Cataclysm-DDA/src/dialogue.h:124:14: error: function 'talk_effect_fun_t::set_u_buy_monster' has a definition with different parameter names [readability-inconsistent-declaration-parameter-name,-warnings-as-errors]
        void set_u_buy_monster( const std::string &monster_id, int cost, int count, bool pacified,
             ^                                     ~~~~~~~~~~
                                                   monster_type_id
/home/travis/build/CleverRaven/Cataclysm-DDA/src/npctalk.cpp:2101:25: note: the definition seen here
void talk_effect_fun_t::set_u_buy_monster( const std::string &monster_type_id, int cost, int count,
                        ^
/home/travis/build/CleverRaven/Cataclysm-DDA/src/dialogue.h:124:14: note: differing parameters are named here: ('monster_id'), in definition: ('monster_type_id')
        void set_u_buy_monster( const std::string &monster_id, int cost, int count, bool pacified,
             ^

Edit: but that's really not the fault of this PR.

[ipcyborg]

Error can be seen at

Well, yes. But I have not changed anything about monster_type_id.
So my question is: should I fix this issue and risk merging conflict?
Or should I wait and somehow re-do that check later, when the issue will be fixed already?

[BevapDin]

It's not the fault of this PR, so you have no need to do anything here. If you want, you can fix this in a separate PR, but otherwise, you can just ignore that error.

[jbytheway]

Looks like the upgrade_time value itself ought to be a time_point, rather than an int, to avoid these sorts of confusions.

[ipcyborg]

Changing upgrade_time to time_point leads to change these fields too: type.age_grow, type.half_life. All of them are used in monster::next_upgrade_time for upgrade calculation.

Also it could lead to change the save format, increase savegame_version and store all these fields in turns (as integers). Is this the correct way?
Or else we could leave the saving/loading in days (not changing save format, only change the in-game type). Looks kind of bad solution.

Looks complex enough to create another PR for it.

[jbytheway]

A separate PR is certainly reasonable.