bugfix: copy binding before run

Copy the binding struct before running it and use this copy to emit the
binding event.

This fixes a crash when the command `reload` is used in a binding when
the binding event is emitted.

testcases/t/238-regress-reload-bindsym.t

@@ -0,0 +1,45 @@
+#!perl
+# vim:ts=4:sw=4:expandtab
+#
+# Please read the following documents before working on tests:
+# • http://build.i3wm.org/docs/testsuite.html
+#   (or docs/testsuite)
+#
+# • http://build.i3wm.org/docs/lib-i3test.html
+#   (alternatively: perldoc ./testcases/lib/i3test.pm)
+#
+# • http://build.i3wm.org/docs/ipc.html
+#   (or docs/ipc)
+#
+# • http://onyxneon.com/books/modern_perl/modern_perl_a4.pdf
+#   (unless you are already familiar with Perl)
+#
+# Test that the binding event works properly
+# Ticket: #1210
+use i3test i3_autostart => 0;
+
+my $config = <<EOT;
+# i3 config file (v4)
+font -misc-fixed-medium-r-normal--13-120-75-75-C-70-iso10646-1
+
+bindsym r reload
+EOT
+
+SKIP: {
+    qx(which xdotool 2> /dev/null);
+
+    skip 'xdotool is required to test the binding event. `[apt-get install|pacman -S] xdotool`', 1 if $?;
+
+    my $pid = launch_with_config($config);
+
+    my $i3 = i3(get_socket_path());
+    $i3->connect->recv;
+
+    qx(xdotool key r);
+
+    does_i3_live;
+
+    exit_gracefully($pid);
+
+}
+done_testing;