Just to add a precision that was not noted previously: the problem is not directly related to sleep but to the "removal" of the battery. Indeed extra spaces are also added when the battery is physically removed (1 extra space) and then reinserted (1 more extra space). Attached is the log produced by
xfce4-power-manager --no-daemon --debug > xfpm.log during these operations.
** (xfce4-power-manager:21641): DEBUG: executed /usr/sbin/xfpm-power-backlight-helper --get-max-brightness; retval: 0 ** (xfce4-power-manager:21641): DEBUG: xfpm_brightness_setup_helper: get-max-brightness returned 15 ** (xfce4-power-manager:21641): DEBUG: xrandr not available, brightness controlled by sysfs helper; min_level=0 max_level=15 ** (xfce4-power-manager:21641): DEBUG: executed /usr/sbin/xfpm-power-backlight-helper --get-brightness; retval: 0 ** (xfce4-power-manager:21641): DEBUG: xfpm_brightness_helper_get_level: get-brightness returned 10 TRACE[xfpm-main.c:200] xfpm_start(): Starting the power manager TRACE[xfpm-xfconf.c:156] xfpm_xfconf_load(): Using default configuration for lock-screen-suspend-hibernate TRACE[xfpm-xfconf.c:156] xfpm_xfconf_load(): Using default configuration for power-save-on-battery TRACE[xfpm-xfconf.c:156] xfpm_xfconf_load(): Using default configuration for show-brightness-popup TRACE[xfpm-xfconf.c:156] xfpm_xfconf_load(): Using default configuration for hibernate-button-action TRACE[xfpm-xfconf.c:156] xfpm_xfconf_load(): Using default configuration for brightness-level-on-ac TRACE[xfpm-xfconf.c:156] xfpm_xfconf_load(): Using default configuration for dpms-on-ac-sleep TRACE[xfpm-xfconf.c:156] xfpm_xfconf_load(): Using default configuration for dpms-on-ac-off TRACE[xfpm-xfconf.c:156] xfpm_xfconf_load(): Using default configuration for dpms-sleep-mode TRACE[xfpm-xfconf.c:156] xfpm_xfconf_load(): Using default configuration for inactivity-sleep-mode TRACE[xfpm-xfconf.c:156] xfpm_xfconf_load(): Using default configuration for spin-down-on-ac TRACE[xfpm-xfconf.c:156] xfpm_xfconf_load(): Using default configuration for spin-down-on-ac-timeout TRACE[xfpm-xfconf.c:156] xfpm_xfconf_load(): Using default configuration for spin-down-on-battery-timeout TRACE[xfpm-power.c:1053] xfpm_power_get_power_devices(): Power device detected at : /org/freedesktop/UPower/devices/line_power_AC TRACE[xfpm-power.c:1053] xfpm_power_get_power_devices(): Power device detected at : /org/freedesktop/UPower/devices/battery_BAT0 TRACE[xfpm-power.c:1011] xfpm_power_add_device(): Battery device detected at : /org/freedesktop/UPower/devices/battery_BAT0: ((XfpmDeviceType) XFPM_DEVICE_TYPE_BATTERY) TRACE[xfpm-button.c:179] xfpm_button_xevent_key(): Grabbed key 124 : ((XfpmButtonKey) BUTTON_POWER_OFF) TRACE[xfpm-button.c:179] xfpm_button_xevent_key(): Grabbed key 213 : ((XfpmButtonKey) BUTTON_HIBERNATE) TRACE[xfpm-button.c:179] xfpm_button_xevent_key(): Grabbed key 150 : ((XfpmButtonKey) BUTTON_SLEEP) TRACE[xfpm-button.c:179] xfpm_button_xevent_key(): Grabbed key 233 : ((XfpmButtonKey) BUTTON_MON_BRIGHTNESS_UP) TRACE[xfpm-button.c:179] xfpm_button_xevent_key(): Grabbed key 232 : ((XfpmButtonKey) BUTTON_MON_BRIGHTNESS_DOWN) TRACE[xfpm-button.c:179] xfpm_button_xevent_key(): Grabbed key 244 : ((XfpmButtonKey) BUTTON_BATTERY) TRACE[xfpm-battery.c:148] xfpm_battery_refresh_visible(): visible=TRUE: ((XfpmShowIcon) SHOW_ICON_ALWAYS) TRACE[xfpm-battery.c:284] xfpm_battery_refresh_icon(): Battery state 4 TRACE[xfpm-power.c:1152] xfpm_power_refresh_adaptor_visible(): Tray icon configuration: : ((XfpmShowIcon) SHOW_ICON_ALWAYS) TRACE[xfpm-power.c:1117] xfpm_power_hide_adapter_icon(): Hide adaptor icon TRACE[xfpm-polkit.c:369] xfpm_polkit_init_data(): Using unix session polkit subject TRACE[xfpm-polkit.c:456] xfpm_polkit_check_auth_intern(): Action=org.freedesktop.upower.suspend is authorized=TRUE TRACE[xfpm-polkit.c:456] xfpm_polkit_check_auth_intern(): Action=org.freedesktop.upower.hibernate is authorized=TRUE TRACE[xfpm-power.c:1152] xfpm_power_refresh_adaptor_visible(): Tray icon configuration: : ((XfpmShowIcon) SHOW_ICON_ALWAYS) TRACE[xfpm-power.c:1117] xfpm_power_hide_adapter_icon(): Hide adaptor icon TRACE[xfpm-polkit.c:456] xfpm_polkit_check_auth_intern(): Action=org.freedesktop.udisks.drive-set-spindown is authorized=TRUE TRACE[xfpm-disks.c:170] xfpm_disks_get_is_auth_to_spin(): Is auth to spin down disks : 1 TRACE[xfpm-disks.c:147] xfpm_disks_set_spin_timeouts(): On Battery=0 spin_down_enabled=0 timeout=800 TRACE[xfpm-backlight.c:318] xfpm_backlight_brightness_on_ac_settings_changed(): Alarm on ac timeout changed 9 TRACE[xfpm-backlight.c:339] xfpm_backlight_brightness_on_battery_settings_changed(): Alarm on battery timeout changed 50 TRACE[xfpm-power.c:1152] xfpm_power_refresh_adaptor_visible(): Tray icon configuration: : ((XfpmShowIcon) SHOW_ICON_ALWAYS) TRACE[xfpm-power.c:1133] xfpm_power_show_adapter_icon(): Showing adaptor icon TRACE[xfpm-power.c:1152] xfpm_power_refresh_adaptor_visible(): Tray icon configuration: : ((XfpmShowIcon) SHOW_ICON_ALWAYS) TRACE[xfpm-power.c:1011] xfpm_power_add_device(): Battery device detected at : /org/freedesktop/UPower/devices/battery_BAT0: ((XfpmDeviceType) XFPM_DEVICE_TYPE_BATTERY) TRACE[xfpm-battery.c:148] xfpm_battery_refresh_visible(): visible=TRUE: ((XfpmShowIcon) SHOW_ICON_ALWAYS) TRACE[xfpm-battery.c:284] xfpm_battery_refresh_icon(): Battery state 4 TRACE[xfpm-power.c:1152] xfpm_power_refresh_adaptor_visible(): Tray icon configuration: : ((XfpmShowIcon) SHOW_ICON_ALWAYS) TRACE[xfpm-power.c:1117] xfpm_power_hide_adapter_icon(): Hide adaptor icon TRACE[xfpm-battery.c:284] xfpm_battery_refresh_icon(): Battery state 4 TRACE[xfpm-battery.c:284] xfpm_battery_refresh_icon(): Battery state 4 TRACE[xfpm-battery.c:284] xfpm_battery_refresh_icon(): Battery state 4 TRACE[xfpm-battery.c:284] xfpm_battery_refresh_icon(): Battery state 4 TRACE[xfpm-battery.c:284] xfpm_battery_refresh_icon(): Battery state 4 TRACE[xfpm-main.c:67] xfpm_quit_signal(): sig 2 TRACE[xfpm-manager.c:576] xfpm_manager_stop(): Stopping TRACE[xfpm-manager.c:164] xfpm_manager_quit(): Exiting TRACE[xfpm-power.c:1117] xfpm_power_hide_adapter_icon(): Hide adaptor icon TRACE[xfpm-polkit.c:239] xfpm_polkit_free_data(): Destroying Polkit data