Adding an ability based on the same ability as an already hidden ability overrides the hidden ability.

[MapNoob]

Here is what I did:

1. Hide the native Inner Fire on a unit - BlzUnitDisableAbility(u, FourCC('Ainf'), false, true)

2. then add a custom Inner Fire to that unit - UnitAddAbility(u, <custom inner fire>)

3. then hide the custom Inner Fire on that unit - BlzUnitDisableAbility(u, <custom inner fire>, false, true)

4. then unhide the native Inner Fire - BlzUnitDisableAbility(u, FourCC('Ainf'), false, false)

After the final step the custom Inner Fire appears, seemingly having overridden the native one which I am unable to make re-appear.

Here is a video showing the problem.

I just spent an entire day debugging this so I thought I would share.

 

[MapNoob]

Also adding the custom Inner Fire to the already existing native Inner Fire also overrides the native when trying to hide it.

This time I did the following:

1. Add custom Inner Fire with UnitAddAbility() to a priest which already has native Inner Fire.
2. Try to hide native Inner Fire with BlzUnitDisableAbility(), but the custom Inner Fire disappeared.
3. Try to hide native Inner Fire with BlzUnitDisableAbility() again, since the custom one was hidden now, but nothing happens.

 

[ThompZon]

Having multiple of the same ability is an issue for many abilities. I'm not surprised of this finding, but good to know

 

[MapNoob]

Having multiple of the same ability is an issue for many abilities. I'm not surprised of this finding, but good to know

That is true. I am not sure if I will revisit this approach again for custom autocasts of abilities without native autocast. I think it could still be useful if you remember to add the abilities to the units in the object editor and then hide the ones you don't want visible on initialization or production. In which case it still works. However this approach with using different abilities for different stages of the same ability has another disadvantage in that if you are group selecting units with different abilities toggled/shown it will show neither.
For this reason I ended up using ability levels and a different icon to indicate difference for the extended autocast I was working on and which I hope I am close done with.

You can check it out HERE