0.9.2 breaks save file of Pokemon White 2 Japanese version

[cloudfish]

Steps to reproduce this:

1. Save game in Japanese White2 in 0.9.1.
2. Load game in Japanese White2 in 0.9.2. Will cause a bunch of "undefined ARM9 instruction" errors and a blank screen.
3. Restart the game. It cannot read the save file and will prompt to start a new game. The save file can still be read by either Japanese or English version of the game in 0.9.1, though.

I guess it has something to do with the new save file handling mechanism?
pnw2jpn.sav.zip
output0.9.1.txt
output0.9.2.txt

[RSDuck]

I cannot reproduce. The savefile loads fine for me in both 0.9.1, 0.9.2 and latest source.

[cloudfish]

It seems that only ROMs of "non-standard" size will not work in 0.9.2. I uploaded my version of the ROM to Google drive. Could you try to reproduce with this ROM? (It is 303MB as opposed to 512MB, and melonDS already warns about this in the log I uploaded)
redacted

A save file is actually not needed to reproduce this. I am able to start a new game (without the save file) using this ROM in 0.9.1, but in 0.9.2, after the initial kana/kanji selection, the game shows a blue screen complaining that the save function is not working.

P.S. While I am able to workaround this using a 512MB Japanese ROM, I used Japanese ROM only to minimize the example; I am actually using a fan-made Chinese translation for which no full-sized version is available.

[Arisotura]

after investigation it appears that your ROM is a patched version for flashcarts and stuff, that has the IR-comm code disabled

however, since 0.9.2, melonDS uses the gamecode to detect that it should emulate an IR cart, and enforces that

(the same ROM only works in 0.9.1 and older because the implementation was a hack, and was more lax)

a 'solution' would be altering the gamecode so it doesn't start with IRxx. we're debating what we can do on our side for these cases. (from an accuracy standpoint, such a patched ROM would not work on its original cart, but it works on flashcarts and such, so this is problematic)

[RSDuck]

fixed by cd4ef57 ca7fb4f pasted wrong link long time ago

[RSDuck]

this issue isn't actually fixed. It seems to be distinct from the one with the bad DSi header. The rom I have which reproduces it seems to be valid (atleast in the places I looked) and still produces the error when not handling it as a DSi cartridge. It works in desmume though.

[RSDuck]

I forgot to mention, the game works without problem when not treating it as an IR rom.

JesseTG/melonds-ds#150 seems to be yet another variation. I don't know whether it has the same root or it is a different one.

[GlazedBelmont]

on my end, I fixed it by repatching my rom. (for the issue linked right above)