Picom: How to exclude QT windows with client decorations?

[arielnmz]

Specifically in the case of Telegram (but I'm sure other QT based applications might have this issue) I see that the menus and other dialogs have this awful blurred space around them:

How do we tell compton to not blur and put shadows on them? I was looking for something similar to _GTK_FRAME_EXTENTS but either I can't figure out the right language to look for it or such a thing simply doesn't exist on QT.

This is what xprop can tell me about some of Telegram menus:

_NET_WM_USER_TIME(CARDINAL) = 6261168
WM_TRANSIENT_FOR(WINDOW): window id # 0x1c00006
_NET_WM_ICON_NAME(UTF8_STRING) =
_NET_WM_ICON(CARDINAL) =    Icon (64 x 64):

[icon excluded]

XdndAware(ATOM) = BITMAP
WM_NAME(STRING) =
_NET_WM_NAME(UTF8_STRING) = "TelegramDesktop"
_MOTIF_WM_HINTS(_MOTIF_WM_HINTS) = 0x2, 0x1, 0x0, 0x0, 0x0
_NET_WM_WINDOW_TYPE(ATOM) = _KDE_NET_WM_WINDOW_TYPE_OVERRIDE, _NET_WM_WINDOW_TYPE_NORMAL
_XEMBED_INFO(_XEMBED_INFO) = 0x0, 0x1
WM_CLIENT_LEADER(WINDOW): window id # 0x1c00008
WM_HINTS(WM_HINTS):
        Client accepts input or input focus: True
        window id # of group leader: 0x1c00008
WM_CLIENT_MACHINE(STRING) = "bc-1.bc"
_NET_WM_PID(CARDINAL) = 2
_NET_WM_SYNC_REQUEST_COUNTER(CARDINAL) = 29360442
WM_CLASS(STRING) = "telegram-desktop", "TelegramDesktop"
WM_PROTOCOLS(ATOM): protocols  WM_DELETE_WINDOW, WM_TAKE_FOCUS, _NET_WM_PING, _NET_WM_SYNC_REQUEST
WM_NORMAL_HINTS(WM_SIZE_HINTS):
        user specified location: 1012, 567
        user specified size: 186 by 220
        window gravity: NorthWest

[arielnmz]

So far I can use this rule to fix the popup menus:

_NET_WM_WINDOW_TYPE:a *= '_KDE_NET_WM_WINDOW_TYPE_OVERRIDE'

But the call dialog still has that weird blur between the frame and the client content:

[arielnmz]

No news on this?

[AdamantGarth]

I'm also having this issue. Thank you for a partial workaround though, @arielnmz.

Is there an issue comment or some documentation where it's explained why picom puts shadows on windows that other compositors do not? I never had an issue with shadows while using Mutter (and forks), Xfwm, Kwin or Compiz. If they're able to tell which windows shouldn't be decorated with shadows, picom should also be able to, right? No disrespect to developers, just genuinely curious.