Suppose a horizontally oriented workspace has two windows open. Issuing "split h" on
the right window creates a nested horizontal container. If we now resize in "width"
direction, the resize doesn't work because it will only operate on the current parent,
which is a container with only one child, so the resize command exits.
This is unexpected behavior from a user point of view. Hence, with this patch, we
ensure that we don't just go up the tree until we find a parent with the correct
orientation, but also keep going if that parent has only a single child.
fixes#2015
When resizing floating windows, changing the height was not correctly
handled. This commit fixes that and adds testcases for shrinking and
growing the width and height of floating windows.
Ingo Bürk