close empty parent containers, add testcase

src/tree.c

@@ -201,6 +201,15 @@ void tree_close(Con *con, bool kill_window) {
     DLOG("focusing %p / %s\n", next, next->name);
     /* TODO: check if the container (or one of its children) was focused */
     con_focus(next);
+
+    /* check if the parent container is empty now and close it */
+    if (parent->type != CT_WORKSPACE &&
+        TAILQ_EMPTY(&(parent->nodes_head))) {
+        DLOG("Closing empty parent container\n");
+        /* TODO: check if this container would swallow any other client and
+         * don’t close it automatically. */
+        tree_close(parent, false);
+    }
 }
 
 /*

testcases/t/30-close-empty-split.t

@@ -0,0 +1,48 @@
+#!perl
+# vim:ts=4:sw=4:expandtab
+#
+# Check if empty split containers are automatically closed.
+#
+use i3test tests => 4;
+use Time::HiRes qw(sleep);
+
+my $i3 = i3("/tmp/nestedcons");
+
+my $tmp = get_unused_workspace();
+$i3->command("workspace $tmp")->recv;
+
+ok(@{get_ws_content($tmp)} == 0, 'no containers yet');
+
+$i3->command('open')->recv;
+my ($nodes, $focus) = get_ws_content($tmp);
+my $first = $focus->[0];
+
+$i3->command('split v')->recv;
+
+($nodes, $focus) = get_ws_content($tmp);
+
+is($nodes->[0]->{focused}, 0, 'split container not focused');
+
+# focus the split container
+$i3->command('level up')->recv;
+($nodes, $focus) = get_ws_content($tmp);
+my $split = $focus->[0];
+$i3->command('level down')->recv;
+
+$i3->command('open')->recv;
+
+($nodes, $focus) = get_ws_content($tmp);
+my $second = $focus->[0];
+
+isnt($first, $second, 'different container focused');
+
+##############################################################
+# close both windows and see if the split container still exists
+##############################################################
+
+$i3->command('kill')->recv;
+$i3->command('kill')->recv;
+($nodes, $focus) = get_ws_content($tmp);
+isnt($nodes->[0]->{id}, $split, 'split container closed');
+
+diag( "Testing i3, Perl $], $^X" );