Thanks @Jildor for the clear and easy How To Reproduce steps 👍

thanks ;)

I'm not sure but maybe HandleStableSwapPet needs the same as HandleStablePet?

get a hunter with a tamed pet
cast Call Stabled Pet (.cast 62757)
keep the pet in the stable
do command .cast 6962
do command .save
I think is related with laspetnumber, maybe we should setlaspetnumber(0) inside HandleStablePet after removepet?

I don't know how many more cases there may be, can't we look for a more generic solution?

I don't have a generic solution, I'm just trying to fix the crashes quite fast so worldserver can stay alive.
One thing about spell 6962 is that it has a custom SpellScript that deals with loading the pet and that code seems to cause a lot of these crashes.

get a hunter with a tamed pet
cast Call Stabled Pet (.cast 62757)
keep the pet in the stable
do command .cast 6962
do command .save

@Jildor to me this is a bug in spell 6962 that it doesn't do the same checks that "Call Pet" does, saying "You do not have a pet to summon"

get a hunter with a tamed pet
cast Call Stabled Pet (.cast 62757)
keep the pet in the stable
do command .cast 6962
do command .save

@Jildor this case has been fixed, now no pet is summoned if it's stabled

get a warlock, summon a pet (by example imp)
.die on warlock character
(now you are dead, so use /g to talk on guild chat and use commands)
.cast 6962 triggered
.revive
summon a different pet (by example voidwalker)
use a mount
dismount

@Jildor this case has been fixed too. Maybe someone with more knowledge about the code could find a different fix but at least we have some workarounds to avoid the crashes

yep, nice 👍
The problem is that there are more ways to generate these crashes, unfortunately I am unable to reproduce all of them, you can reproduce this easily too: #26492 (comment)

get a warlock and summon a pet (by example imp)
.npc add temp 34775
mount in vehicle and switch to right or left seat
summon a different pet (by example voidwalker)

It's too hard to find more ways to reproduce these crashes

@Jildor well the first step is to fix fast the obvious ones, then find a more generic solution that still works with all the cases we found (and ofc remove the fast temporary fix)

get a warlock and summon a pet (by example imp)
.npc add temp 34775
mount in vehicle and switch to right or left seat
summon a different pet (by example voidwalker)

this is fixed now with a more generic "when loading a pet from PET_SAVE_NOT_IN_SLOT and CurrentPet is not empty, remove the CurrentPet".

got a strange behavior now:

• summon pet A with warlock
• enter vehicle 34775
• change seat to the ones where you can cast spells
• summon pet B
• exit vehicle
• mount a normal mount
• dismount
• pet A is resummoned instead of pet B

but I guess summoning the wrong pet is better than triggering an assert

@Jildor I changed the fix for Case 1 to be more generic, moving the check in Pet.cpp .

• get a hunter with a tamed pet
• cast Call Stabled Pet (.cast 62757)
• keep the pet in the stable
• do command .cast 6962
• do command .save

This case is now handled in a generic way, unstabling the pet and updating the required variables to avoid any assert. If this is not the desired behavior, just return false in Pet::LoadFromDB() in the "if" case I added (I'm not caring at all for blizzlikeness right now, just fixing asserts)

Case 2 now works with the same fix as Case 3, even if ingame it looks a bit strange. When dismounting, the stable pet will become current and the stable interface shows the pet duplicated until Call Stable is called again.

I removed the change added in 6052cdf which can be added again if needed (no idea if returnReagents parameter should be false or true in that case)

Case 4 now works with the same fix as Case 5. This means we have 5 different cases fixed by 3 different changes, all done in Pet::LoadPetFromDB() :

• if the pet being loaded is already the current one, don't re-summon the same one
• if there is already a pet, remove it
• if the pet is stabled, unstable it

These are fallback checks that kick in only when the caller has not taken care already of these scenarios. For example Call Pet will still show the ingame message "You don't have an active pet" when the pet is stabled.

@Jildor could you please test latest version of this PR, running once more through the cases you reported and maybe some more that didn't crash before but that you tested already ? I hope the current code looks more promising to you 🤞

this case continue crashing:
#26492 (comment)

@Jildor that case works for me using 770bda9

• create a new warlock character
• summon a pet (by example imp)
• mount on a vehicle that allow use spells (by example 34775) and switch to left or right
• passenger seat
• cast any other summon pet (by example summon voidwalker)

@Jildor case 6 fixed too

tested all cases, I can't reproduce the crashes 👍

Thank you for the PR! 😄

A new case:

• create a new hunter character
• .cast 1515 to tame a pet
• .cast 62757 and put the pet into the stable
• .cast 1515 to tame a new pet
• .cast 62757
• swap slots between new and old pets then server will crash

@shenhuyong did that case happen before this PR too ?

Edit: nvm, found the issue from this PR

• create a new hunter character
• .cast 1515 to tame a pet
• .cast 62757 and put the pet into the stable
• .cast 1515 to tame a new pet
• .cast 62757
• swap slots between new and old pets then server will crash

fixed by 22a5b0f , caused by a missing change from this PR in Pet Swap opcode