Allow single-child non-default layout cons to be moved between outputs

Includes a test case to verify the behaviour of 'move <direction>'.
Fixes #1603.

src/move.c

@@ -249,6 +249,14 @@ void tree_move(Con *con, int direction) {
                         ? AFTER
                         : BEFORE);
         insert_con_into(con, target, position);
+    } else if (con->parent->parent->type == CT_WORKSPACE &&
+               con->parent->layout != L_DEFAULT &&
+               con_num_children(con->parent) == 1) {
+        /* Con is the lone child of a non-default layout container at the edge
+         * of the workspace. Treat it as though the workspace is its parent
+         * and move it to the next output. */
+        DLOG("Grandparent is workspace\n");
+        move_to_output_directed(con, direction);
     } else {
         DLOG("Moving into container above\n");
         position = (direction == D_UP || direction == D_LEFT ? BEFORE : AFTER);

testcases/t/524-move.t

@@ -0,0 +1,99 @@
+#!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)
+#
+# Tests the behaviour of 'move <direction>' when moving containers across
+# outputs on workspaces that have non-default layouts.
+# Ticket: #1603
+# Bug still in: 4.10.1-40-g0ad097e
+use List::Util qw(first);
+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
+
+fake-outputs 1024x768+0+0,1024x768+1024+0,1024x768+1024+768,1024x768+0+768
+
+workspace left-top output fake-0
+workspace right-top output fake-1
+workspace right-bottom output fake-2
+workspace left-bottom output fake-3
+
+workspace_layout stacked
+EOT
+
+my $pid = launch_with_config($config);
+
+#####################################################################
+# Create two windows in the upper left workspace and move them
+# clockwise around the workspaces until the end up where they began.
+#####################################################################
+
+cmd 'workspace left-top';
+
+my $first = open_window(wm_class => 'first');
+my $second = open_window(wm_class => 'second');
+
+is_num_children('left-top', 1, 'one child on left-top');
+is_num_children('right-top', 0, 'no children on right-top');
+
+# Move the second window into its own stacked container.
+cmd 'move right';
+is_num_children('left-top', 2, 'two children on left-top');
+
+# Move the second window onto the upper right workspace.
+cmd 'move right';
+is_num_children('left-top', 1, 'one child on left-top');
+is_num_children('right-top', 1, 'one child on right-top');
+
+# Move the first window onto the upper right workspace.
+cmd '[class="first"] move right';
+is_num_children('left-top', 0, 'no children on left-top');
+is_num_children('right-top', 2, 'two children on right-top');
+
+# Move the second window onto the lower right workspace.
+cmd '[class="second"] move down, move down';
+is_num_children('right-top', 1, 'one child on right-top');
+is_num_children('right-bottom', 1, 'two children on right-bottom');
+
+# Move the first window onto the lower right workspace.
+cmd '[class="first"] move down';
+is_num_children('right-top', 0, 'no children on right-top');
+is_num_children('right-bottom', 2, 'two children on right-bottom');
+
+# Move the second windo onto the lower left workspace.
+cmd '[class="second"] move left, move left';
+is_num_children('right-bottom', 1, 'one child on right-bottom');
+is_num_children('left-bottom', 1, 'one on left-bottom');
+
+# Move the first window onto the lower left workspace.
+cmd '[class="first"] move left';
+is_num_children('right-bottom', 0, 'no children on right-bottom');
+is_num_children('left-bottom', 2, 'two children on left-bottom');
+
+# Move the second window onto the upper left workspace.
+cmd '[class="second"] move up, move up';
+is_num_children('left-bottom', 1, 'one child on left-bottom');
+is_num_children('left-top', 1, 'one child on left-top');
+
+# Move the first window onto the upper left workspace.
+cmd '[class="first"] move up';
+is_num_children('left-bottom', 0, 'no children on left-bottom');
+is_num_children('left-top', 2, 'two children on left-top');
+
+exit_gracefully($pid);
+
+done_testing;