ping @ryanofsky

This seems ok. I think it could make sense for -nodatadir and -datadir= on the command line to override any datadir string in the configuration file and override any datadir in qt settings, and use default platform datadir as if no value was ever specified.

Or alternately, it could make sense for -nodatadir to print an error, because it's similar enough to -nowallet, -nowalletdir, -nopid, -norpccookiefile options where you might want to be able to disable bitcoin from creating files & directories, but different from those options because bitcoin can't function without a datadir.

In either case, I think the PR description here should be updated to be more self contained. I think an ideal PR description would first say what the change in behavior is, then give reasons for the change, and only then go into deeper history and assigning credit for ideas, to be comprehensible as possible without digging into previous discussion.

Also a change like this should have release notes.

The following sections might be updated with supplementary metadata relevant to reviewers and maintainers.

Conflicts

No conflicts as of last run.

@ryanofsky

In either case, I think the PR description here should be updated to be more self contained. I think an ideal PR description would first say what the change in behavior is, then give reasons for the change, and only then go into deeper history and assigning credit for ideas, to be comprehensible as possible without digging into previous discussion.

The PR description has been updated.

I would rather see just -datadir or -datadir="" as a way to set the default and override config.

-nodatadir doesn't make any sense to me.

Each arg could have a flag whether it can be negated or not. For instance ArgsManager::AddArg(..., bool allow_negated = true).

@promag

I would rather see just -datadir or -datadir="" as a way to set the default and override config.
-nodatadir doesn't make any sense to me.

You and @ryanofsky have convinced me. Going to implement your suggestion tonight.

Each arg could have a flag whether it can be negated or not. For instance ArgsManager::AddArg(..., bool allow_negated = true).

Could you look into #16097?

@ryanofsky and @promag Thank you for your reviews.

I would rather see just -datadir or -datadir="" as a way to set the default and override config.

Done. The OP has been updated.

... it could make sense for -nodatadir to print an error...

I'd rather use a more general solution like #16097.

Closed in favor of #15864.

See: 740d41c#r306906349