Let non-damage skills bypass player_invincible_time

[MrKeiKun]

Pull Request Prelude

• I have followed proper Hercules code styling.
• I have read and understood the contribution guidelines before making this PR.
• I am aware that this PR may be closed if the above-mentioned criteria are not fulfilled.

Changes Proposed

battle_check_target() blocked all skill targeting against a player under player_invincible_time (post-spawn/teleport grace period), except for a hardcoded two-skill allowlist (PR_SANCTUARY, PR_MAGNIFICAT) added in 2015 as an admittedly incomplete fix for bugreport:8397.

On official servers, invincibility only protects against damage and other hostile/offensive effects — non-damage skills such as SA_DISPELL, songs (BA_POEMBRAGI, DC_SERVICEFORYOU), and other buffs/debuffs should apply immediately regardless of the target's invincible state.

This replaces the two-skill allowlist with a general check against skill->get_nk(skill_id) & NK_NO_DAMAGE, so any non-damage skill bypasses the invincibility gate by default instead of needing to be special-cased individually. Equip-strip skills (RG_STRIPWEAPON/STRIPSHIELD/STRIPARMOR/STRIPHELM, ST_FULLSTRIP, SC_STRIPACCESSARY, GC_WEAPONCRUSH) are kept blocked despite being NK_NO_DAMAGE, since they're still an offensive debuff. Plain melee attacks (skill_id == 0) are unaffected and remain blocked.

Issues addressed: #966

Thanks @kyeme and @Playtester

[kyeme]

@MrKeiKun
It seems that player_invincible_time against monsters is broken after these changes.

For example, if you log in while there is a monster nearby, the monster will attack you immediately instead of waiting for player_invincible_time to expire.

[MrKeiKun]

@MrKeiKun It seems that player_invincible_time against monsters is broken after these changes.

For example, if you log in while there is a monster nearby, the monster will attack you immediately instead of waiting for player_invincible_time to expire.

try now @kyeme interestingly, battle_check_target() bypassed invincible_timer based on battle->get_current_skill(src), which returns unit_data::skill_id. i never noticed that earlier 😆

[kyeme]

@MrKeiKun Tested the fix, and it's working correctly now. Thank you.