World: r4wp

I might patch this NONE case unless anyone has a good reason to leave 
it in place?

(At the moment, you get usage info on stderr. The current r3 just 
segfaults on Linux.)

It's none propagation I guess. Because dealing with or ignoring nones 
is easier to do in Rebol than writing conditional code around everything 
to avoid triggering errors.

Okay, so I guess we just need to handle the NONE rather than attempting 
to browse it

The BROWSE code should explicitly do nothing if passed a NONE. It 
certainly shouldn't segfault.

If it doesn't explicitly do nothing, that's a bug.

Just return unset, I guess.

Okay, fixing now.

not R_NONE?

No, that returns none. Whatever BROWSE normally returns.

It normally returns NONE.

R_NONE

But I think the original intent was for NONE to open an empty browser. 
Can't find any references for that.

Weird. Shouldn't it return unset?

https://github.com/rebol/r3/blob/master/src/core/n-io.c#L499

Should probably rather return the URL, that would be more useful 
:)

That treatment of a none argument makes sense, Andreas. However, 
the function should return unset, like PRINT.

If we can agree on something, I'll push that the change.

BrianH: So, R_UNSET?

That's independent of the OSX open fix in any case.

Sure. And in the has-a-url case too.

So better just file a CC issue for the `browse none` crash, and we 
can discuss the desired design in there.

Yeah, maybe two pulls.

Okay, I'll pop this in a separate branch.

Marc, did you file a ticket for this? If not, I can repurpose #1921 
for this.

Win32 browse opens an empty browser for NONE.

I didn't, no.

Please don't repurpose 1921 :)

Let 1921 stay dismissed, OK.

One ticket for missing BROWSE on OSX, another one for the browse 
none crash.

https://github.com/rebol/r3/blob/master/src/os/win32/host-lib.c#L640

Will do. And I'm still revamping the REWORD ticket example code.

Well, I'll briefly write up the crash ticket.

If you could write both I'd appreciate it. I have limited R3 time 
today, I have an R2 task I have to work on.

Ok.

https://github.com/0branch/r3/commit/95e3481ffba473f9191b918dd2eb890e764ff32a

If that looks good, I can submit pull requests for both issues once 
Andreas has written up the issues?

I'm not sure if the second is the desired change :)

MarcS: one open questions is if we should use the __APPLE__ define 
(is that defined for iOS as well?) or rather use the R3-specific 
platform defines.

Oh, did I misunderstand?

Win32 handles a none URL gracefully, just opening an "empty" browser.

Oh, okay. But this meets Brian's suggestion?

Yes.

A function should only return none if returning another value is 
a valid option. If it never returns a value, it shouyld return unset.

Incidentally, there's no simple way to browse to none using the current 
technique (as far as I can see).

BrianH: oh okay, so this is a unit type / void.

Yeah.

e.g., on MacOSX, open uses the format of its argument to determine 
the appropriate handler. I'd imagine xdg-open does the same.

And i doubt browsing to file:/// is the desired default.

(Replace file:/// with anything else, I think the point stands.)