From 9e4a858285af360dce4956141c71e94efbcb96a3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20Gr=C3=A4=C3=9Flin?= <mgraesslin@kde.org>
Date: Wed, 16 Nov 2016 08:36:51 +0100
Subject: [PATCH] Fix DebugConsole::initGLTab

The initGLTab used GLPlatform::instance to determine whether OpenGL is
used. It assumed a nullptr would mean no GL. But GLPlatform is a
singleton which does not follow KWin's internal semantics. If there is
no instance it will be created. Thus it's never null.

This caused a heap-buffer-overflow as recorded by build.kde.org in case
one just casts the scene pointer to SceneOpenGL.

With this change this is fixed and inited correctly by verifying through
the EffectsHandler whether opengl is used.
---
 debug_console.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/debug_console.cpp b/debug_console.cpp
index 48e152919e..f57d3f0c7f 100644
--- a/debug_console.cpp
+++ b/debug_console.cpp
@@ -516,12 +516,12 @@ DebugConsole::~DebugConsole() = default;
 
 void DebugConsole::initGLTab()
 {
-    GLPlatform *gl = GLPlatform::instance();
-    if (!gl) {
+    if (!effects || !effects->isOpenGLCompositing()) {
         m_ui->noOpenGLLabel->setVisible(true);
         m_ui->glInfoScrollArea->setVisible(false);
         return;
     }
+    GLPlatform *gl = GLPlatform::instance();
     m_ui->noOpenGLLabel->setVisible(false);
     m_ui->glInfoScrollArea->setVisible(true);
     m_ui->glVendorStringLabel->setText(QString::fromLocal8Bit(gl->glVendorString()));