git-gui: bring wish process to front on Mac

On Mac OS X, any application that is started from the Terminal will open
behind all running applications; as a work-around, manually bring ourselves
to the front. (Stolen from gitk, commit 76bf6ff.)

We do this as the very first thing, so that any message boxes that might pop
up during the rest of the startup sequence are actually seen by the user.

[PT: added catch and moved down to ensure Tk has been loaded]

Signed-off-by: Stefan Haller <stefan@haller-berlin.de>
Signed-off-by: Pat Thoyts <patthoyts@users.sourceforge.net>

git-gui.sh

@@ -135,6 +135,20 @@ proc strcat {args} {
 ::msgcat::mcload $oguimsg
 unset oguimsg
 
+######################################################################
+##
+## 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]]
+	}
+}
+
 ######################################################################
 ##
 ## read only globals