When leaving fullscreen, set focus to con which was opened during fullscreen (+testcase) (Thanks dothebart)

testcases/t/56-fullscreen-focus.t

@@ -0,0 +1,65 @@
+#!perl
+# vim:ts=4:sw=4:expandtab
+#
+# Test if new containers get focused when there is a fullscreen container at
+# the time of launching the new one.
+#
+use X11::XCB qw(:all);
+use Time::HiRes qw(sleep);
+use i3test;
+
+BEGIN {
+    use_ok('X11::XCB::Window');
+}
+
+my $x = X11::XCB::Connection->new;
+my $i3 = i3("/tmp/nestedcons");
+
+my $tmp = get_unused_workspace;
+cmd "workspace $tmp";
+
+#####################################################################
+# open the left window
+#####################################################################
+
+my $left = open_standard_window($x, '#ff0000');
+
+is($x->input_focus, $left->id, 'left window focused');
+
+diag("left = " . $left->id);
+
+#####################################################################
+# Open the right window
+#####################################################################
+
+my $right = open_standard_window($x, '#00ff00');
+
+diag("right = " . $right->id);
+
+#####################################################################
+# Set the right window to fullscreen
+#####################################################################
+cmd 'nop setting fullscreen';
+cmd 'fullscreen';
+
+#####################################################################
+# Open a third window
+#####################################################################
+
+my $third = open_standard_window($x, '#0000ff');
+
+diag("third = " . $third->id);
+
+# move the fullscreen window to a different ws
+
+my $tmp2 = get_unused_workspace;
+
+cmd "move workspace $tmp2";
+
+# verify that the third window has the focus
+
+sleep 0.25;
+
+is($x->input_focus, $third->id, 'third window focused');
+
+done_testing;