Xephyr resizeable window goes into a loop

[totaam]

Issue migrated from trac ticket # 1248

component: server | priority: major | resolution: invalid | keywords: x11 Xephyr resize

2016-07-07 12:44:36: antoine created the issue

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Just start Xephyr as a child: --start=Xephyr -resizeable, then it goes into a spin as soon as you try to resize it. Log attached.

[totaam]

2016-07-07 12:45:22: antoine uploaded file Xephyr-resize-loop.log (20.5 KiB)

log of server endless resize loop

[totaam]

2016-07-07 13:34:43: antoine changed status from new to assigned

[totaam]

2016-07-07 13:34:43: antoine commented

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Sequence of events from the log sample above:

• client sends _process_configure_window with the new dimensions
• updateprop fires the notification, which triggers XpraServer._window_resized_signaled where we correctly detect that the window geometry matches the desktop manager's value (which we just updated from the client)
• the _do_update_client_geometry sends a ConfigureNotify, which we ignore on the corral window: we only invalidate the pixmap, on the client window we end up in resize_corral_window which is a no-op since the dimensions match

All further events follow the same pattern. That's before the problem occurs.
At some point we stop resizing yet the stream of ConfigureNotify events does not stop: whilst we resize the corral window (up or down), Xephyr is busy resizing its own window to match, and then we try to match this size.. causing the loop:

resize_corral_window() resize from (712, 481) to (705, 480)
resize_corral_window() resize from (705, 480) to (712, 481)
resize_corral_window() resize from (712, 481) to (705, 480)

etc

Maybe #723 would help with this? Or this patch: ephyr: Don't configure window while responding to configure events

[totaam]

2016-07-07 13:38:04: antoine uploaded file Xephyr-resize-loop2.log (24.5 KiB)

actual ConfigureNotify loop

[totaam]

2016-07-07 17:25:46: antoine uploaded file rate-limit-corral-resize.patch (2.4 KiB)

trying to rate limit corral window resizing

[totaam]

2016-07-07 17:59:38: antoine uploaded file Xephyr-resize.patch (2.0 KiB)

upstream patch

[totaam]

2016-07-07 18:04:07: antoine changed status from assigned to closed

[totaam]

2016-07-07 18:04:07: antoine set resolution to invalid

[totaam]

2016-07-07 18:04:07: antoine commented

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The bug is fixed in Xephyr by applying the patch attached, I have requested its inclusion in a future stable update: Re: ephyr: Don't configure window while responding to configure events

Closing as not an xpra bug.
Follow up ticket: #1249, further Xephyr geometry issues.

[totaam]

2016-07-12 17:52:23: antoine commented

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Milestone renamed