Gitk doesn't work on macOS Mojave

Hi

You have probably heard this by now already, but gitk doesn’t work on macOS 10.14 - because it uses Apple Events, And apps on 10.14 require user to give them permissions to control other apps with Apple Events.

Here is what I get when I try running it on my machine with beta 4 installed:

Error in startup script: 58:102: execution error: Not authorized to send Apple events to System Events. (-1743)
    while executing
"exec osascript -e [format {
        tell application "System Events"
            set frontmost of processes whose unix id is %d to true
        end te..."
    invoked from within
"if {[tk windowingsystem] eq "aqua"} {
    exec osascript -e [format {
        tell application "System Events"
            set frontmost of processes ..."
    (file "/usr/local/bin/gitk" line 12212)

And Apple doesn’t allow to add apps to “Automation” :( 

Best regards. And thanks for git :)

On Thu, Jul 19, 2018 at 2:48 PM Evgeny Cherpak <cherpake@me.com> wrote:

This hasn't been reported, so thanks for bringing it up.

Fortunately, this feature is merely a convenience, not otherwise critical to gitk functioning. It would be ideal if someone running Mojave could devise up a patch to work around the problem (either by skipping this code on Mojave or discovering a different way to bring the application to the foreground). An alternative would be to revert 76bf6ff93e (gitk: On OSX, bring the gitk window to front, 2013-04-24), which introduced this code.

(Note, however, that the gitk project is dormant, so it's not clear if such a patch will be picked up.)

It seems this code placed at the end of the file, after getcommits() does the trick:

if {[tk windowingsystem] eq "aqua"} { 
	set openscript [format { 
		open -a \"$(ps -p %d -o comm=)\"
	} [pid] ]
    exec osascript -e [format {
		do shell script "%s"
    } "$openscript” ]
}

[please reply inline rather than top-posting]

On Thu, Jul 19, 2018 at 5:11 PM Evgeny Cherpak <cherpake@me.com> wrote:

Interesting idea. A shortcoming of this approach is that it's non-deterministic. It will bring _any_ running gitk to the foreground, rather than the one mentioned by PID, which would be a potentially confusing regression. Such confusion _might_ be worse than simply not foregrounding the application at all (though that's a matter of opinion). Unfortunately, the 'open' command doesn't let you do so by PID, and Googling shows only answers which predate Mojave (that is, they all suggest Apple Events).

To avoid such a regression on older MacOS's, it would be nice to retain the Apple Events code, but that would mean gitk would need to do a version check or something to avoid executing the Apple Events code on Mojave.

By the way, the same problem presumably afflicts "git gui", which has identical code in it for foregrounding the application. Does that match with your experience?

[re-adding cc:git]

On Fri, Jul 20, 2018 at 12:38 AM Evgeny Cherpak <cherpake@me.com> wrote:

Looking more closely, the code in "git gui" is catching and silently ignoring errors:

    ## On Mac, bring the current Wish process window to front
    if {[tk windowingsystem] eq "aqua"} {
        catch {
            exec osascript -e [format {
                tell application "System Events"
                    set frontmost of processes whose unix id is %d to true
                end tell
            } [pid]]
        }
    }

which explains why you don't see the "Not authorized to send Apple events" error you see with gitk, and also explains why the application doesn't get focus.

So, updating gitk to mirror git-gui might be one way forward.

👍

On MacOS, a "wish" application started from the terminal opens in the background, thus doesn't match user expectation that a newly-launched application ought to be placed in the foreground. To address this shortcoming, both gitk and git-gui use Apple Events to send a message to "System Events" instructing it to foreground the "wish" application by PID.

Unfortunately, MacOS 10.14 tightens restrictions on Apple Events, requiring explicit granting of permission to control applications in this fashion, and apparently such granting for "Automation" is not allowed at all[1]. As a consequence gitk crashes outright at launch time with a "Not authorized to send Apple events to System Events" error, thus is entirely unusable on "Mojave".

In contrast, git-gui does not crash since it deliberately[2] catches and ignores Apple Events errors. This does mean that git-gui will not automatically become the foreground application on "Mojave", which is a minor inconvenience but far better than crashing outright as gitk does.

Update gitk to catch and ignore Apple Events errors, mirroring git-gui's behavior, to avoid this crash.

(Finding and implementing an alternate approach to foregrounding the "wish" application on "Mojave" may be desirable but is outside the scope of this crash fix.)

[1]: https://public-inbox.org/git/D295145E-7596-4409-9681-D8ADBB9EBB0C@me.com/ [2]: https://public-inbox.org/git/CABNJ2G+h3zh+=wLA0KHjUn8TsfhqUK1Kn-1_=6hnXVRJUPhuuA@mail.gmail.com/

Reported-by: Evgeny Cherpak <cherpake@me.com>
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
---

Lack of 'catch' in the 'osascript' invocation in gitk was recognized as a potential problem as far back as June 2013 [3,4]; now it's biting "Mojave" users, making gitk unusable.

[3]: https://public-inbox.org/git/7vk3m7yukc.fsf@alter.siamese.dyndns.org/ [4]: https://public-inbox.org/git/1l424u5.uk987q18u3oxfM%25lists@haller-berlin.de/

 gitk-git/gitk | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)