Restoring edge tiled windows on Wayland shrinks them

[mtvoid]

I'm running Ubuntu 18.04 with a vanilla GNOME session under Wayland (the issue presents with the default Ubuntu session too). I've encountered this issue with applications that use Client-Side window decorations, which is most of the GNOME applications. Windows with borders drawn through the window manager do not have this issue.

Steps to reproduce:
1. Open an application that uses client-side decorations, e.g. gnome-terminal.
2. Edge tile the window by snapping the window to the left or right screen edge via dragging or Super+left/right keyboard shortcut.
3. Unsnap the window to restore it to its non-tiled state.

Expected behaviour:
The position and dimensions of the window after undoing the edge tiling should be restored to exactly what it was prior to tiling.

Observed behaviour:
Every time the window is unsnapped from the edge, its size gets smaller. Repeating it over and over will lead to it eventually shrinking to the minimum possible size.

I've found this issue only with client-side decorated windows, and only while restoring from split view / edge tiling. Restoring from a normal maximized state is ok.

[mtvoid (mtvoid)]

The bug shows up only in a Wayland session. The behaviour is normal under Xorg. Quite possibly an issue with GTK+, which is improperly handling the sizing of client-side decorated windows when tiling/untiling them.

[Daniel van Vugt (vanvugt)]

Please report this bug the the mutter developers here:
https://gitlab.gnome.org/GNOME/mutter/issues

[Daniel van Vugt (vanvugt)]

... and tell us the URL of the new bug.

[mtvoid (mtvoid)]

I've found a recent bug report for this issue on the GitLab site for mutter:
https://gitlab.gnome.org/GNOME/mutter/issues/140

This also requires me to correct my initial bug report. The issue is unrelated to client-side decorated windows, but affects all native Wayland windows, while XWayland windows are unaffected.

[Christian Rauch (christianrauch)]

The mutter MR https://gitlab.gnome.org/GNOME/mutter/merge_requests/801 should fix that issue.