Don't change default find-file behaviour

[Wilfred]

Currently, opening any file that is read-only and not owned by the
current user triggers a root login prompt. This occurs for viewing
system files (e.g /etc/fstab), built-in elisp
libraries (e.g. simple.el.gz) and simply viewing files owned by other
users on a shared system.

We can't assume that this is the behaviour users want, and changing
built-in functions without asking is surprising.

Fixes #20.

[bbatsov]

I'll take a look at this. There's a writable check that should prevent this for files you can actually write to. Add if the hook's removed it should be documented.

[bbatsov]

To be clear - I agree with the spirit of the change, but:

• this functionality should be discoverable
• this functionality shouldn't cause the effect you described even when enabled

[Wilfred]

@bbatsov I'm still not clear what the purpose is of adding this function to the hook. crux-reopen-as-root is definitely useful, but when would users want it automatically called?

[Wilfred]

@bbatsov ping, would you be able to take a look at this?

[bbatsov]

@bbatsov I'm still not clear what the purpose is of adding this function to the hook. crux-reopen-as-root is definitely useful, but when would users want it automatically called?

The idea was that you won't have to think about the command at all as it would be applied automatically to some files if necessary. As I said before, I think the behaviour you've experienced is a bug in the file check done before reopening the file. The original idea was for this to affect just files owned by root. Anyways, I can imagine this being annoying, but I'm guessing some people also find it useful...

[Wilfred]

There are two issues here:

1: This applies to reading all files that aren't owned by the current user. For example, (find-file "/var/log/postgresql.log") triggers this even though the file isn't owned by root. I think this is the bug in the check you're referring to.

2: Users who want to simply view a file owned by root are prompted for sudo credentials. If they don't have sudo credentials, or don't want to use them, they're prompted every single time. This is my concern.

How would you feel about making this opt-in? We could move this line of code to the readme or define a crux-reopen-as-root-mode. Currently this change in behaviour is not documented AFAICS.

[bbatsov]

How would you feel about making this opt-in? We could move this line of code to the readme or define a crux-reopen-as-root-mode. Currently this change in behaviour is not documented AFAICS.

I agree. Probably making this a trivial mode that simply adds and removes this hook would be best. Or we can hook into saving the file so people are not prompted to do anything unless they actually try to change it...

[Wilfred]

Wonderful, thanks for being supportive :)

I've written a little global minor mode, let me know what you think.

[bbatsov]

Looks good. Just mention it somewhere in the README.

[Wilfred]

README updated.