[ChangeLog][QPA][eglfs] Fix crash when using cursors and multiple GL contexts

The hash from QOpenGLContext* to cursor texture/shader data can
accumulate dangling pointers if the program uses multiple contexts on
the same screen. This is fixed by moving the cursor data into the
platform context. The code for deleting the texture and shader program
is omitted as it is tied to the life time of the context and the GL
context deletes its resources automatically upon destruction.

Task-number: QTBUG-65119
Change-Id: Ic3b8e5669d14949af811bdf047e7d47000216180
Reviewed-by: Laszlo Agocs <laszlo.agocs@qt.io>

1 files changed, 4 insertions, 11 deletions

diff --git a/src/plugins/platforms/eglfs/api/qeglfscursor.cpp b/src/plugins/platforms/eglfs/api/qeglfscursor.cpp
index f46206cab5..22319fcc66 100644
--- a/src/plugins/platforms/eglfs/api/qeglfscursor.cpp
+++ b/src/plugins/platforms/eglfs/api/qeglfscursor.cpp
@@ -40,10 +40,10 @@
 #include "qeglfscursor_p.h"
 #include "qeglfsintegration_p.h"
 #include "qeglfsscreen_p.h"
+#include "qeglfscontext_p.h"
 
 #include <qpa/qwindowsysteminterface.h>
 #include <QtGui/QOpenGLContext>
-#include <QtGui/QOpenGLShaderProgram>
 #include <QtCore/QFile>
 #include <QtCore/QJsonDocument>
 #include <QtCore/QJsonArray>
@@ -115,13 +115,6 @@ void QEglFSCursorDeviceListener::onDeviceListChanged(QInputDeviceManager::Device
 
 void QEglFSCursor::resetResources()
 {
-    if (QOpenGLContext *ctx = QOpenGLContext::currentContext()) {
-        GraphicsContextData &gfx(m_gfx[ctx]);
-        delete gfx.program;
-        glDeleteTextures(1, &gfx.customCursorTexture);
-        glDeleteTextures(1, &gfx.atlasTexture);
-        gfx = GraphicsContextData();
-    }
     m_cursor.customCursorPending = !m_cursor.customCursorImage.isNull();
 }
 
@@ -144,8 +137,8 @@ void QEglFSCursor::createShaderPrograms()
         "   gl_FragColor = texture2D(texture, textureCoord).bgra;\n"
         "}\n";
 
-    GraphicsContextData &gfx(m_gfx[QOpenGLContext::currentContext()]);
-    gfx.program = new QOpenGLShaderProgram;
+    QEglFSCursorData &gfx = static_cast<QEglFSContext*>(QOpenGLContext::currentContext()->handle())->cursorData;
+    gfx.program.reset(new QOpenGLShaderProgram);
     gfx.program->addCacheableShaderFromSourceCode(QOpenGLShader::Vertex, textureVertexProgram);
     gfx.program->addCacheableShaderFromSourceCode(QOpenGLShader::Fragment, textureFragmentProgram);
     gfx.program->bindAttributeLocation("vertexCoordEntry", 0);
@@ -475,7 +468,7 @@ void QEglFSCursor::draw(const QRectF &r)
 {
     StateSaver stateSaver;
 
-    GraphicsContextData &gfx(m_gfx[QOpenGLContext::currentContext()]);
+    QEglFSCursorData &gfx = static_cast<QEglFSContext*>(QOpenGLContext::currentContext()->handle())->cursorData;
     if (!gfx.program) {
         // one time initialization
         initializeOpenGLFunctions();