Graceful fallback to readonly mode if RDB can't be opened readwrite

[JoeOsborn]

My guess is that this will fix #15566 , but I can't test on UWP.

This PR also replaces some stray tabs with spaces.

[GABO1423]

I should be able to test this later today, I'll let you know what results I can find.

[GABO1423]

This sadly did not fix the issue @JoeOsborn

[JoeOsborn]

Interesting. The only code path I changed connected with just listing database entries was in opening the DB with different flags—the rest of the changes concerned find_entry, find_index, and create_index. Are those used in RA’s database listing code?

[JoeOsborn]

Sorry for the CI noise, I’m trying to fix this from my phone!

[GABO1423]

I got the strength to get to the computer, I'll get to testing this now

[GABO1423]

Good news, these new commits did the trick!

[JoeOsborn]

I’m glad it works. I still don’t know why the fallback to opening readonly didn’t do the trick, but it does feel more correct to only open the file readonly when we don’t need to write to it.

[LibretroAdmin]

Would you guys like me to squash and merge this PR?

Would that fix the issue for Xbox?

[GABO1423]

Would you guys like me to squash and merge this PR?

Would that fix the issue for Xbox?

Yes, the screenshots above show that this fixes the issue.