0002383: AI infinitely loops with this save - secSkill desync

(0006303)
SXX (administrator)
2016-01-18 18:46
edited on: 2016-01-18 18:58

This one require HotA to be enabled.

PS: Assign to myself, it's pathfinder issue.

(0006304)
vmarkovtsev (developer)
2016-01-18 20:04

https://github.com/vcmi/vcmi/pull/157 [^]

(0006305)
SXX (administrator)
2016-01-18 20:35
edited on: 2016-01-18 20:36

I don't think this is valid fix for anything. Also network code is look correct for me, but condition naming is weird.

There basically two issues:
1 - First of all AI for some reason attempt to visit border guard indefinitely. Likely some bug in VCAI or Quest / border guard.

2 - Second it's pathfinder tell VCAI on client that it's have enough movement points while movement cost on server end up being different. Such situations are possible in complex cases because pathfinder code not yet used on server for movement validation and decade old spaghetti code validate movement instead.

(0006448)
SXX (administrator)
2016-02-25 02:54

So I started working on this one. It's really weird, but looks like there is serious desync going. Green AI hero (King Unaghor) does have basic pathfinding skill in client gamestate, but not on server.

This it's reason why pathfinder pretend that hero can still move while server think it's not possible.

(0006452)
SXX (administrator)
2016-02-25 05:59

Problem that made AI to visit border guard over and over again is fixed in 0001590. Though I have no idea why desync occur so I'll leave this one open.

(0006572)
SXX (administrator)
2016-08-19 20:29

Little update on this one. There is some chance that desync in that save was originally caused by some issue with both heroes initialization and random generator desync.

Check 0002459 for more details.

(0006576)
SXX (administrator)
2016-08-20 15:03

Oops. End up there is actually cuz of that desync.

So it's exactly it: problem with skills caused by fact that HeroRecruited::applyGs use random generator from gamestate and it's desynced after game start.

In the end it's occur only when hero have default expirience, but not type set so it's called from gamestate like that:
HeroRecruited::applyGs -> initObj -> initHero -> levelUpAutomatically

(0006646)
SXX (administrator)
2016-09-11 18:56

Fixed with PR209 merge:
https://github.com/vcmi/vcmi/commit/2543e068acd7e91ad4234ddfd7622c5e4fac664f [^]

Issue History
Date Modified	Username	Field	Change
2016-01-18 15:14	vmarkovtsev	New Issue
2016-01-18 15:14	vmarkovtsev	Status	new => assigned
2016-01-18 15:14	vmarkovtsev	Assigned To	=> Warmonger
2016-01-18 15:14	vmarkovtsev	File Added: The Lord of War.h3m
2016-01-18 15:14	vmarkovtsev	File Added: save_lord_of_war.zip
2016-01-18 18:46	SXX	Note Added: 0006303
2016-01-18 18:46	SXX	Assigned To	Warmonger => SXX
2016-01-18 18:58	SXX	Note Edited: 0006303	View Revisions
2016-01-18 20:04	vmarkovtsev	Note Added: 0006304
2016-01-18 20:35	SXX	Note Added: 0006305
2016-01-18 20:36	SXX	Note Edited: 0006305	View Revisions
2016-01-30 11:33	SXX	Relationship added	related to 0002326
2016-02-25 02:54	SXX	Note Added: 0006448
2016-02-25 03:17	SXX	Relationship added	related to 0001590
2016-02-25 03:17	SXX	Relationship deleted	related to 0002326
2016-02-25 03:22	SXX	Summary	AI infinitely loops with this save => AI infinitely loops with this save - secSkill desync
2016-02-25 05:59	SXX	Note Added: 0006452
2016-08-19 20:27	SXX	Relationship added	related to 0002459
2016-08-19 20:29	SXX	Note Added: 0006572
2016-08-19 20:44	SXX	Relationship deleted	related to 0002459
2016-08-19 20:44	SXX	Relationship added	child of 0002459
2016-08-19 20:45	SXX	Note Added: 0006573
2016-08-19 20:45	SXX	Note Edited: 0006573	View Revisions
2016-08-20 14:39	SXX	Note Deleted: 0006573
2016-08-20 15:03	SXX	Note Added: 0006576
2016-09-11 18:56	SXX	Note Added: 0006646
2016-09-11 18:56	SXX	Status	assigned => resolved
2016-09-11 18:56	SXX	Fixed in Version	=> 0.99
2016-09-11 18:56	SXX	Resolution	open => fixed
2022-04-12 11:04	Povelitel	Status	resolved => closed

Notes
(0006303) SXX (administrator) 2016-01-18 18:46 edited on: 2016-01-18 18:58	This one require HotA to be enabled. PS: Assign to myself, it's pathfinder issue.

(0006304) vmarkovtsev (developer) 2016-01-18 20:04	https://github.com/vcmi/vcmi/pull/157 [^]

(0006305) SXX (administrator) 2016-01-18 20:35 edited on: 2016-01-18 20:36	I don't think this is valid fix for anything. Also network code is look correct for me, but condition naming is weird. There basically two issues: 1 - First of all AI for some reason attempt to visit border guard indefinitely. Likely some bug in VCAI or Quest / border guard. 2 - Second it's pathfinder tell VCAI on client that it's have enough movement points while movement cost on server end up being different. Such situations are possible in complex cases because pathfinder code not yet used on server for movement validation and decade old spaghetti code validate movement instead.

(0006448) SXX (administrator) 2016-02-25 02:54	So I started working on this one. It's really weird, but looks like there is serious desync going. Green AI hero (King Unaghor) does have basic pathfinding skill in client gamestate, but not on server. This it's reason why pathfinder pretend that hero can still move while server think it's not possible.

(0006452) SXX (administrator) 2016-02-25 05:59	Problem that made AI to visit border guard over and over again is fixed in 0001590. Though I have no idea why desync occur so I'll leave this one open.

(0006572) SXX (administrator) 2016-08-19 20:29	Little update on this one. There is some chance that desync in that save was originally caused by some issue with both heroes initialization and random generator desync. Check 0002459 for more details.

(0006576) SXX (administrator) 2016-08-20 15:03	Oops. End up there is actually cuz of that desync. So it's exactly it: problem with skills caused by fact that HeroRecruited::applyGs use random generator from gamestate and it's desynced after game start. In the end it's occur only when hero have default expirience, but not type set so it's called from gamestate like that: HeroRecruited::applyGs -> initObj -> initHero -> levelUpAutomatically

(0006646) SXX (administrator) 2016-09-11 18:56	Fixed with PR209 merge: https://github.com/vcmi/vcmi/commit/2543e068acd7e91ad4234ddfd7622c5e4fac664f [^]