Sometimes does not notice changes in xinerama / multihead configuration

[leonerd]

(originally reported to debian at https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=946972)

Version: 1:1.11.90-1.1+b1

An older version of sawfish (though I don't have a record of which) would reliably notice when the xinerama setup changed, adding or removing the second display I have on my laptop's displayport adapter. While the second display was unavailable, sawfish would never try to place new windows over the "dead" head, and they would all reliably appear on the laptop's internal screen.

On the current version, this sometimes does not happen. When it fails to notice the external display being taken away, new windows often get placed on the dead area of the external monitor, currently inaccessible, and I have to use menus/keyboard shortcuts to move the window onto the visible laptop-screen area. When it fails to notice the external display returning, the display remains blank and windows cannot be moved to it. However I know this isn't just that the display itself is inactive because placing the mouse on the far righthand edge of the internal laptop display will show the cursor overflowing onto that second screen. X11 itself is drawing there, but sawfish refuses to move any windows into it.

This failure to notice changes seems unreliable though - sometimes the change will be noticed and placement will be correct; sometimes not. I have noticed no particular pattern to when it does or doesn't take effect.

-- System Information:
Debian Release: bullseye/sid
APT prefers testing
APT policy: (990, 'testing'), (500, 'unstable-debug'), (500, 'testing-debug'), (500, 'unstable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 5.2.0-3-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8), LANGUAGE=en_GB:en (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages sawfish depends on:
ii libc6 2.29-3
ii libgdk-pixbuf2.0-0 2.40.0+dfsg-1
ii libglib2.0-0 2.62.3-2
ii libgtk2.0-0 2.24.32-4
ii libice6 2:1.0.9-2
ii libpango-1.0-0 1.42.4-7
ii libpangoxft-1.0-0 1.42.4-7
ii librep16 0.92.5-3+b5
ii libsm6 2:1.2.3-1
ii libx11-6 2:1.6.8-1
ii libxext6 2:1.3.3-1+b2
ii libxft2 2.3.2-2
ii libxinerama1 2:1.1.4-2
ii libxrandr2 2:1.5.1-1
ii libxtst6 2:1.2.3-1
ii rep 0.92.5-3+b5
ii rep-gtk 1:0.90.8.2-3
ii sawfish-data 1:1.11.90-1.1
ii xfce4-terminal [x-terminal-emulator] 0.8.8-1+b1
ii xterm [x-terminal-emulator] 351-1

sawfish recommends no packages.

Versions of packages sawfish suggests:
pn gnome-control-center
ii menu 2.1.47+b1
pn yelp

-- Configuration Files:
/etc/X11/sawfish/site-init.d/00debian.jl changed:
; load the sawfish defaults
(require 'sawfish-defaults)

-- no debconf information