Cannot configure behaviour of MODAL windows

Submitted by epe..@..pnt.fr

Assigned to Olivier Fourdan @olivier

Link to original bug (#13447)

Description

We use X11 servers on centos 7 and XFCE4. The client sends Windows to this centos X11 server and we need to generate a modal Windows (ie Windows which is not able to go out with the mouse till you click close button)

To have a modal windows we have always used by the past the option MWM_INPUT_SYSTEM_MODAL for the parameter XmNmwmInputMode

Result of xprop | grep MOTIF this Windows is

MOTIF_WM_INTS(_MOTIF_WM_HINTS) = 0x7,0x3C,0xfffffff5, 0x2, 0x0 seems to be correct

Can not understand why centos 7 doesn't interpret the modal windows * even with changing property of Windows using xprop I have not effect it is always possible to click out of this window with the mouse

I have tried: xprop -id windid -f _MOTIF_WM_HINTS 32a -set _MOTIF_WM_HINTS "0x7, 0x3c, 0xffffff5, 0x2 , 0x0" which is MWM_INPUT_SYSTEM_MODAL

xprop -id windid -f _MOTIF_WM_HINTS 32a -set _MOTIF_WM_HINTS "0x7, 0x3c, 0xffffff5, 0x3 , 0x0" which is MWM_INPUT_FULL_APPLICATION_MODAL

But no change in behaviour