Dialogs not visible multi-screen osx

[Eric Le Lay]

Mac OS 10.11.1
XQuartz 2.7.8
Inkscape 0.91 from Inkscape-0.91-1-x11-10.7-x86_64.dmg
I have 2 identical screens side by side (left and right).
Inkscape opens on the right one (that has the dock) and displays fine the empty document and toolbars in a new window.
I choose File > Document Settings (to change the size of the page)
The dialog doesn't appear on the right screen, nor the left
It's not hidden: I've closed all other windows and moved the inkscape window to see if it's not behind.
I've tried XQuartz > Windows > Bring all to front or navigate, without effect.

I can see the dialog way on the left when I show all windows. For reference, the inkscape window occupies pretty much all my right screen, so it seems the dialog is in the top left corner of the left screen but there is nothing showing there.

I can solve this by disabling the 2nd screen or configure them as video copy.
Or by moving the inkscape window to the left screen, then clicking on the main window in the area where the dialog would be brings it to life.

I understand it's plausibly an XQuartz bug...

[su_v (suv-lp)]

Thank you for taking the time to file this report - the issue is known (Incompatibility of XQuartz with Apple's changed default behavior of Spaces with multi-screen setups) and already tracked in
* Bug #1244397 “XQuartz on OS X 10.9 and later: limited support for multi-monitor setups”
  https://bugs.launchpad.net/inkscape/+bug/1244397

The recommended workaround by the core XQuartz developer/maintainer is to «Turn off "Displays have separate spaces" in Mission Control if you need to use X11 across multiple displays».

[Eric Le Lay (er5c)]

thanks and sorry for the noise.
I had searched with "multi-screen" and "osx" instead of xquartz.

I'll use the work-arround disabling distinct spaces for distinct desktops.