Fix context leak when destroying canvas that was never properly shown.

Sharecontext gets created even if the canvas doesn't create the regular
context, but it wasn't destroyed unless regular context also existed.

Change-Id: Ib975ff65c4138000b4a2f1277fe56c9d5109c626
Task-number: QTBUG-50369
Reviewed-by: Tomi Korpipää <tomi.korpipaa@theqtcompany.com>
Reviewed-by: Pasi Keränen <pasi.keranen@theqtcompany.com>

1 files changed, 42 insertions, 42 deletions

diff --git a/src/imports/qtcanvas3d/canvasrenderer.cpp b/src/imports/qtcanvas3d/canvasrenderer.cpp
index 86ca838..7939c3b 100644
--- a/src/imports/qtcanvas3d/canvasrenderer.cpp
+++ b/src/imports/qtcanvas3d/canvasrenderer.cpp
@@ -315,64 +315,64 @@ void CanvasRenderer::init(QQuickWindow *window, const CanvasContextAttributes &c
  */
 void CanvasRenderer::shutDown()
 {
-    if (!m_glContext)
-        return;
-
     QMutexLocker locker(&m_shutdownMutex);
 
-    m_fps = 0;
+    if (m_glContext) {
+        if (m_renderTarget == Canvas::RenderTargetOffscreenBuffer)
+            m_glContext->makeCurrent(m_offscreenSurface);
+
+        m_commandQueue.clearResourceMaps();
 
-    if (m_renderTarget == Canvas::RenderTargetOffscreenBuffer)
-        m_glContext->makeCurrent(m_offscreenSurface);
+        deleteCommandData();
+        m_executeQueue.clear();
 
-    m_commandQueue.clearResourceMaps();
+        delete m_renderFbo;
+        delete m_displayFbo;
+        delete m_antialiasFbo;
 
-    deleteCommandData();
-    m_executeQueue.clear();
+        if (m_renderTarget == Canvas::RenderTargetOffscreenBuffer) {
+            delete m_alphaMultiplierFbo;
+            m_alphaMultiplierFbo = 0;
+            glDeleteBuffers(1, &m_alphaMultiplierUVBuffer);
+            glDeleteBuffers(1, &m_alphaMultiplierVertexBuffer);
+            m_alphaMultiplierUVBuffer = 0;
+            m_alphaMultiplierVertexBuffer = 0;
+            delete m_alphaMultiplierProgram;
+            delete m_alphaMultiplierVertexShader;
+            delete m_alphaMultiplierFragmentShader;
+            m_alphaMultiplierProgram = 0;
+            m_alphaMultiplierVertexShader = 0;
+            m_alphaMultiplierFragmentShader = 0;
 
-    delete m_renderFbo;
-    delete m_displayFbo;
-    delete m_antialiasFbo;
+            m_glContext->doneCurrent();
+            delete m_glContext;
+        }
 
-    if (m_renderTarget == Canvas::RenderTargetOffscreenBuffer) {
-        delete m_alphaMultiplierFbo;
-        m_alphaMultiplierFbo = 0;
-        glDeleteBuffers(1, &m_alphaMultiplierUVBuffer);
-        glDeleteBuffers(1, &m_alphaMultiplierVertexBuffer);
-        m_alphaMultiplierUVBuffer = 0;
-        m_alphaMultiplierVertexBuffer = 0;
-        delete m_alphaMultiplierProgram;
-        delete m_alphaMultiplierVertexShader;
-        delete m_alphaMultiplierFragmentShader;
-        m_alphaMultiplierProgram = 0;
-        m_alphaMultiplierVertexShader = 0;
-        m_alphaMultiplierFragmentShader = 0;
+        m_renderFbo = 0;
+        m_displayFbo = 0;
+        m_antialiasFbo = 0;
 
-        m_glContext->doneCurrent();
-        delete m_glContext;
-    }
+        // m_offscreenSurface is owned by main thread, as on some platforms that is required.
+        if (m_offscreenSurface) {
+            m_offscreenSurface->deleteLater();
+            m_offscreenSurface = 0;
+        }
 
-    m_renderFbo = 0;
-    m_displayFbo = 0;
-    m_antialiasFbo = 0;
+        m_currentFramebufferId = 0;
+        m_forceViewportRect = QRect();
 
-    delete m_glContextShare;
+        delete m_stateStore;
+        m_stateStore = 0;
 
-    // m_offscreenSurface is owned by main thread, as on some platforms that is required.
-    if (m_offscreenSurface) {
-        m_offscreenSurface->deleteLater();
-        m_offscreenSurface = 0;
+        m_glContext = 0;
     }
 
-    m_glContext = 0;
+    delete m_glContextShare;
+
     m_glContextQt = 0;
     m_glContextShare = 0;
 
-    m_currentFramebufferId = 0;
-    m_forceViewportRect = QRect();
-
-    delete m_stateStore;
-    m_stateStore = 0;
+    m_fps = 0;
 }
 
 /*!