Assertion in `bytesToSlotCount` fails in Deltarune Chapter 5

[matteofo]

System Info

Platform: Arch Linux 7.1.4-arch1-1
Backend: SDL3

Issue description

Butterscotch hangs during the Susie outfit minigame at the start of Deltarune Chapter 5 due to a failed assertion in the bytesToSlotCount function in vm.c:

static int32_t bytesToSlotCount(VMContext* ctx, int32_t nativeBytes, int32_t stackPos) {
    int32_t slots = 0;
    int32_t remaining = nativeBytes;
    while (remaining > 0) {
        slots++;
        require(stackPos >= slots); // 2. if you remove the assertion below, this one fails later on
        uint8_t slotGmlType = ctx->stack.slots[stackPos - slots].gmlStackType;
        remaining -= gmlTypeNativeSize(slotGmlType);
    }
    require(remaining == 0); // Byte count must align exactly to slot boundaries
    // ^^^ 1. this fails
    return slots;
}

Here's a log from Butterscotch up to the hang :)

[cobaltgit]

#360 seems to fix this issue, just awaiting the green light on it.

[cobaltgit]

#340 as well, need to re-test it as it seems to crash the save menu when I select an option on the bottom to my right (i.e. moving from Copy to Erase or Ch 4 Files to Japanese)

[matteofo]

I see, thanks! I tried pulling #360 and recompiling and that indeed made it work :)