scumm - why autosave uses game slot 1?

[Lebostein]

I play Indy 4 and I get a warning message, that I use save slot 1 because this slot is reserved for autosave.
I deleted save slot 1 for autosaving. But if I press load, I see no autosave in slot 1. The slot remains empty (even after 10 minutes of playing).
If I uses save slot 1 again, 5 minutes later I get the warning for save slot again...

What is going on?

[Praetorian]

I play Indy 4 and I get a warning message, that I use save slot 1 because this slot is reserved for autosave.
I deleted save slot 1 for autosaving. But if I press load, I see no autosave in slot 1. The slot remains empty (even after 10 minutes of playing).
If I uses save slot 1 again, 5 minutes later I get the warning for save slot again...

What is going on?

First, slot 1 of the classic save/load menu for the game is slot 0 for ScummVM save system. This is the default autosave slot, although I believe engines can set it to something else.

For this particular case, it seems that the SCUMM engine disables autosaving when the option to use the classic Save/Load menus is checked for the game.
But, currently this indeed behaves in a buggy way since:
- the user has no way to know this is the case (eg. there could be a note next to the checkbox option)
- the game still regularly prompts if there's a game saved in the "autosave" reserved slot, even though it won't actually autosave regardless of what the user selects in the prompt. I think there's a method to use here to easily fix this (ie. override canSaveAutosaveCurrently())

Re: The "5 minutes" thing. According to the code, if the autosaving fails (for whatever reason the system failed to write the save file) or the user chose "ignore" on the warning prompt, then it will be re-attempted after 5 minutes regardless of the setting for the autosave period in Global Options.
In the SCUMM case however, the autosave does not really "fail". It is just skipped. So the warning prompt should come up again if you save on Slot 1 from the classic menu, after x minutes, where x is your setting for autosaving.

tl;dr this seems like an intended thing that needs a bit of tweaking to avoid needlessly prompting the user for autosaving.