regression in window placement

Before #517 (closed): new, non-maximized windows were placed below the panel bar. When windows are maximized, the will occupy full screen below the panel bar.

Now: new, non-maximized windows have their title bar placed below the panel. When maximized, they will again occupy the full screen below the panel.

$ xrandr
Screen 0: minimum 8 x 8, current 3840 x 1080, maximum 32767 x 32767
eDP1 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 310mm x 170mm
   1920x1080     60.00*+  59.93    48.00
   1680x1050     59.88
   1400x1050     59.98
   1600x900      60.00    59.95    59.82
   1280x1024     60.02
   1400x900      59.96    59.88
   1280x960      60.00
   1368x768      60.00    59.88    59.85
   1280x800      59.81    59.91
   1280x720      59.86    60.00    59.74
   1024x768      60.00
   1024x576      60.00    59.90    59.82
   960x540       60.00    59.63    59.82
   800x600       60.32    56.25
   864x486       60.00    59.92    59.57
   640x480       59.94
   720x405       59.51    60.00    58.99
   640x360       59.84    59.32    60.00
DP1 disconnected (normal left inverted right x axis y axis)
HDMI1 connected primary 1920x1080+1920+0 (normal left inverted right x axis y axis) 480mm x 270mm
   1920x1080     60.00*+  50.00    59.94
   1920x1080i    60.00    50.00    59.94
   1680x1050     59.88
   1280x1024     75.02    60.02
   1440x900      59.90
   1280x960      60.00
   1280x720      60.00    50.00    59.94
   1024x768      75.03    70.07    60.00
   832x624       74.55
   800x600       72.19    75.00    60.32    56.25
   720x576       50.00
   720x480       60.00    59.94
   640x480       75.00    72.81    66.67    60.00    59.94
   720x400       70.08
HDMI2 disconnected (normal left inverted right x axis y axis)
VIRTUAL1 disconnected (normal left inverted right x axis y axis)

$ xprop
_NET_FRAME_EXTENTS(CARDINAL) = 0, 0, 0, 0
_NET_WM_ALLOWED_ACTIONS(ATOM) = _NET_WM_ACTION_CLOSE, _NET_WM_ACTION_FULLSCREEN, _NET_WM_ACTION_CHANGE_DESKTOP, _NET_WM_ACTION_STICK
WM_STATE(WM_STATE):
                window state: Normal
                icon window: 0xbf2dd700
_NET_WM_DESKTOP(CARDINAL) = 4294967295
_NET_WM_STATE(ATOM) = _NET_WM_STATE_STICKY, _NET_WM_STATE_SKIP_PAGER, _NET_WM_STATE_SKIP_TASKBAR, _NET_WM_STATE_FOCUSED
WM_HINTS(WM_HINTS):
                Client accepts input or input focus: True
                Initial state is Normal State.
                window id # of group leader: 0x1000001
_GTK_THEME_VARIANT(UTF8_STRING) =
XdndAware(ATOM) = BITMAP
_NET_WM_STRUT_PARTIAL(CARDINAL) = 0, 0, 21, 0, 0, 0, 0, 0, 1920, 3839, 0, 0
_NET_WM_OPAQUE_REGION(CARDINAL) = 7, 0, 1906, 7, 0, 7, 1920, 14
_MOTIF_WM_HINTS(_MOTIF_WM_HINTS) = 0x2, 0x0, 0x0, 0x0, 0x0
WM_WINDOW_ROLE(STRING) = "Panel"
_NET_WM_WINDOW_TYPE(ATOM) = _NET_WM_WINDOW_TYPE_DOCK
_NET_WM_SYNC_REQUEST_COUNTER(CARDINAL) = 16777221, 16777222
_NET_WM_USER_TIME_WINDOW(WINDOW): window id # 0x1000004
WM_CLIENT_LEADER(WINDOW): window id # 0x1000001
_NET_WM_PID(CARDINAL) = 1914
WM_LOCALE_NAME(STRING) = "de_DE.UTF-8"
WM_CLIENT_MACHINE(STRING) = "latitude"
WM_NORMAL_HINTS(WM_SIZE_HINTS):
                program specified location: 0, 0
                program specified minimum size: 1920 by 21
                program specified maximum size: 1920 by 21
                program specified base size: 0 by 0
                window gravity: Static
WM_PROTOCOLS(ATOM): protocols  WM_DELETE_WINDOW, WM_TAKE_FOCUS, _NET_WM_PING, _NET_WM_SYNC_REQUEST
WM_CLASS(STRING) = "xfce4-panel", "Xfce4-panel"
WM_ICON_NAME(STRING) = "xfce4-panel"
_NET_WM_ICON_NAME(UTF8_STRING) = "xfce4-panel"
WM_NAME(STRING) = "xfce4-panel"
_NET_WM_NAME(UTF8_STRING) = "xfce4-panel"