Add a kind of test for wibox shape support

Signed-off-by: Uli Schlachter <psychon@znc.in>

tests/test-wibox-shape.lua

@@ -0,0 +1,31 @@
+-- A quick-and-dirty test of wibox shapes ("Does it error out?")
+
+local runner = require("_runner")
+local wibox = require("wibox")
+local shape = require("gears.shape")
+
+local was_drawn
+local widget = wibox.widget.base.make_widget()
+function widget.draw()
+    was_drawn = true
+end
+
+local wb = wibox {
+    shape = shape.powerline,
+    widget = widget,
+    border_width = 42,
+}
+wb:geometry(screen[1].geometry)
+wb.visible = true
+
+runner.run_steps({
+    function()
+        assert(wb.shape == shape.powerline)
+        assert(wb.shape_bounding) -- This is a memory leak! Don't copy!
+        if was_drawn then
+            return true
+        end
+    end
+})
+
+-- vim: filetype=lua:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:textwidth=80