Re: macOS fullscreen crashes

[Alan Third <alan@idiocy.org>]

On Sat, Dec 01, 2018 at 12:21:13PM +0100, Charles A. Roelli wrote:
> > Date: Fri, 30 Nov 2018 11:04:58 +0000
> > From: Alan Third <alan@idiocy.org>
> > 
> > We still occasionally receive bug reports about crashes on macOS
> > 10.12+ caused by macOS turning fullscreen windows into ‘tabbed’
> > windows. I’ve also seen it discussed in a few places round the web.
> > 
> > We currently have a compile‐time check to include code that fixes this
> > on 10.12+, and it can be over‐ridden if Emacs is being built on an
> > older version of macOS but is expected to run on 10.12+, however it is
> > clearly not doing the job.
> 
> Do you know why?  It sounds like people are using builds made on an
> older macOS without setting MAC_OS_X_VERSION_MIN_REQUIRED and
> MAC_OS_X_VERSION_MAX_ALLOWED appropriately.  Maybe we should call out
> in NEWS (in branch emacs-26, that is) and/or nextstep/README how
> exactly to do this.

Yes, you’re right, we should probably try education first.

BTW, it looks like there are two different sets of macros for this,
there are the ones we’re using, and newer ones defined in
Availability.h that have two underscores at the start. It looks like
the newer ones are a bit neater. If you use

    -mmacosx-version-min=10.x

it disables a great many deprecation warnings that you get if you just
set MAC_OS_X_VERSION_MIN_REQUIRED like we do.

I don’t think we should be changing anything at the moment, and I
don’t know if those macros are available on macOS 10.6 so they may not
be much use to us, but it is nice how it makes the compiler output a
lot quieter.

So, anyway, perhaps we want to put something like this in
nextstep/INSTALL:

Targeting different macOS versions
----------------------------------

The Emacs build process automatically enables or disables macOS
features according to the version of macOS it is being built on. It is
possible to over-ride this automatic configuration if you are
targeting a different version of macOS, or wish to build one
executable that is able to enable or disable features at run-time.

To build a version compatible with an older version of macOS use this
flag:

  -DMAC_OS_X_VERSION_MIN_REQUIRED=x

and to build for a newer version of macOS:

  -DMAC_OS_X_VERSION_MAX_ALLOWED=x

For example, to enable run-time checks for features available between
macOS 10.6, and 10.12 inclusive:

  ./configure --with-ns CFLAGS="-DMAC_OS_X_VERSION_MIN_REQUIRED=1060 \
    -DMAC_OS_X_VERSION_MAX_ALLOWED=101200 -g3 -O2"

The macOS version numbers are formatted as 10x0 for macOS up to 10.10,
and 10xx00 for macOS 10.10 and above. A full list is available in
/usr/include/AvailabilityMacros.h.
-- 
Alan Third