Client: Improve handling of 0xH and Wx0 xdg_toplevel configure events

The compositor can send a configure event with 0xH and Wx0 when it wants
the window to have some concrete size along one dimension but wants the
client to pick the size along the other dimension.

Change-Id: I2e72017d4a71b19a930da24fa5c58b6ce672fb94
Reviewed-by: David Edmundson <davidedmundson@kde.org>

1 files changed, 27 insertions, 8 deletions

diff --git a/src/plugins/shellintegration/xdg-shell/qwaylandxdgshell.cpp b/src/plugins/shellintegration/xdg-shell/qwaylandxdgshell.cpp
index c0d7a7d4..9bd5209f 100644
--- a/src/plugins/shellintegration/xdg-shell/qwaylandxdgshell.cpp
+++ b/src/plugins/shellintegration/xdg-shell/qwaylandxdgshell.cpp
@@ -58,19 +58,38 @@ void QWaylandXdgSurface::Toplevel::applyConfigure()
     m_xdgSurface->m_window->handleToplevelWindowTilingStatesChanged(m_toplevelStates);
     m_xdgSurface->m_window->handleWindowStatesChanged(m_pending.states);
 
-    if (m_pending.size.isEmpty()) {
-        // An empty size in the configure means it's up to the client to choose the size
-        bool normalPending = !(m_pending.states & (Qt::WindowMaximized|Qt::WindowFullScreen));
-        if (normalPending && !m_normalSize.isEmpty()) {
-            QSize size = m_normalSize;
+    // If the width or height is zero, the client should decide the size on its own.
+    QSize surfaceSize;
+
+    if (m_pending.size.width() > 0) {
+        surfaceSize.setWidth(m_pending.size.width());
+    } else {
+        if (Q_UNLIKELY(m_pending.states & (Qt::WindowMaximized | Qt::WindowFullScreen))) {
+            qCWarning(lcQpaWayland) << "Configure event with maximized or fullscreen state contains invalid width:" << m_pending.size.width();
+        } else {
+            int width = m_normalSize.width();
             if (!m_pending.bounds.isEmpty())
-                size = size.boundedTo(m_pending.bounds);
-            m_xdgSurface->m_window->resizeFromApplyConfigure(size);
+                width = std::min(width, m_pending.bounds.width());
+            surfaceSize.setWidth(width);
         }
+    }
+
+    if (m_pending.size.height() > 0) {
+        surfaceSize.setHeight(m_pending.size.height());
     } else {
-        m_xdgSurface->m_window->resizeFromApplyConfigure(m_pending.size);
+        if (Q_UNLIKELY(m_pending.states & (Qt::WindowMaximized | Qt::WindowFullScreen))) {
+            qCWarning(lcQpaWayland) << "Configure event with maximized or fullscreen state contains invalid height:" << m_pending.size.height();
+        } else {
+            int height = m_normalSize.height();
+            if (!m_pending.bounds.isEmpty())
+                height = std::min(height, m_pending.bounds.height());
+            surfaceSize.setHeight(height);
+        }
     }
 
+    if (!surfaceSize.isEmpty())
+        m_xdgSurface->m_window->resizeFromApplyConfigure(surfaceSize);
+
     m_applied = m_pending;
     qCDebug(lcQpaWayland) << "Applied pending xdg_toplevel configure event:" << m_applied.size << m_applied.states;
 }