Avoid invalid geometry of internal clients through plasma surface interface

Summary:
Internal KWin windows might be not in sync with their PlasmaShellSurface.
This could be a problem in general, but for now atleast guard against
invalid setPosition requests.

BUG: 386304

Test Plan: Manually

Reviewers: #kwin, davidedmundson

Subscribers: davidedmundson, ngraham, graesslin, kwin

Tags: #kwin

Maniphest Tasks: T8771

Differential Revision: https://phabricator.kde.org/D13084

shell_client.cpp

@@ -1234,7 +1234,12 @@ void ShellClient::installPlasmaShellSurface(PlasmaShellSurfaceInterface *surface
 {
     m_plasmaShellSurface = surface;
     auto updatePosition = [this, surface] {
-        doSetGeometry(QRect(surface->position(), m_clientSize + QSize(borderLeft() + borderRight(), borderTop() + borderBottom())));
+        QRect rect = QRect(surface->position(), m_clientSize + QSize(borderLeft() + borderRight(), borderTop() + borderBottom()));
+        // Shell surfaces of internal windows are sometimes desync to current value.
+        // Make sure to not set window geometry of internal windows to invalid values (bug 386304)
+        if (!m_internal || rect.isValid()) {
+            doSetGeometry(rect);
+        }
     };
     auto updateRole = [this, surface] {
         NET::WindowType type = NET::Unknown;