CSD styled windows do not detect when re-parented to a decoration
Submitted by Martin Gräßlin
Created attachment 276122 Reparented to a WM provided decoration
A window manager might reparent the GTK+ window to a WM provided decoration. Not all window managers support the Motif hints or just ignore them.
Steps to reproduce:
- Run KWin
- Start gtk3-demo (3.12.1)
- Alt+F3 -> More Actions -> [ ] No Border
KWin adds decoration, then there is the shadow, then the CSD border (see attached screenshot)
GTK removes the custom decoration as WM sets a decoration. At least shadow should be removed.
Note: this is an issue really important for reparenting tiling window managers not supporting Motif hints.