From 2c0a03e9aea13831d05ac03996949f888afd5085 Mon Sep 17 00:00:00 2001
From: Jaehak Lee <jaehak.lee@mobis.co.kr>
Date: Sun, 8 Nov 2020 11:40:06 +0900
Subject: [PATCH 07/19] Do not try to eglMakeCurrent for unintended case

The QSGThreadedRenderLoop::hide can be called at twice,
when the QWindowPrivate::setVisible(false) is called.

The eglSurface is EGL_NO_SURFACE when the second QSGThreadedRenderLoop::hide is
called. And if EGL_KHR_surfaceless_context is supported, the eglMakeCurrent
don't return the false.

But this case is not intended. So, add the defence code for above case.

Fixes: QTBUG-88277
Change-Id: Ia9e5990303e98f0eedc48531e5af62ff9961f419
Reviewed-by: Laszlo Agocs <laszlo.agocs@qt.io>
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@qt.io>
---
 .../client/wayland-egl/qwaylandglcontext.cpp                | 6 ++++++
 .../client/wayland-egl/qwaylandglcontext.h                  | 1 +
 2 files changed, 7 insertions(+)

diff --git a/src/hardwareintegration/client/wayland-egl/qwaylandglcontext.cpp b/src/hardwareintegration/client/wayland-egl/qwaylandglcontext.cpp
index ccebf43d..681f82f4 100644
--- a/src/hardwareintegration/client/wayland-egl/qwaylandglcontext.cpp
+++ b/src/hardwareintegration/client/wayland-egl/qwaylandglcontext.cpp
@@ -336,6 +336,8 @@ QWaylandGLContext::QWaylandGLContext(EGLDisplay eglDisplay, QWaylandDisplay *dis
                                << "It may also cause the event loop to freeze in some situations";
     }
 
+    m_supportSurfaceLessContext = q_hasEglExtension(m_eglDisplay, "EGL_KHR_surfaceless_context");
+
     updateGLFormat();
 }
 
@@ -439,6 +441,10 @@ bool QWaylandGLContext::makeCurrent(QPlatformSurface *surface)
         eglSurface = window->eglSurface();
     }
 
+    if (eglSurface == EGL_NO_SURFACE && m_supportSurfaceLessContext) {
+        return false;
+    }
+
     if (!eglMakeCurrent(m_eglDisplay, eglSurface, eglSurface, m_context)) {
         qWarning("QWaylandGLContext::makeCurrent: eglError: %x, this: %p \n", eglGetError(), this);
         window->setCanResize(true);
diff --git a/src/hardwareintegration/client/wayland-egl/qwaylandglcontext.h b/src/hardwareintegration/client/wayland-egl/qwaylandglcontext.h
index 46c7bb76..93edaec0 100644
--- a/src/hardwareintegration/client/wayland-egl/qwaylandglcontext.h
+++ b/src/hardwareintegration/client/wayland-egl/qwaylandglcontext.h
@@ -93,6 +93,7 @@ private:
     DecorationsBlitter *m_blitter = nullptr;
     uint m_api;
     bool m_supportNonBlockingSwap = true;
+    bool m_supportSurfaceLessContext = false;
 };
 
 }
-- 
2.31.1