[plasma/kwin] src: opengl/eglcontext: mark makeCurrent as nodiscard

Git commit 6c523e20d1280b397d2437246ee86649fd8b0bbb by Xaver Hugl.
Committed on 03/08/2026 at 15:09.
Pushed by zamundaaa into branch 'master'.

opengl/eglcontext: mark makeCurrent as nodiscard

And fix the cases where it was wrongly ignored. Some of these would in a GPU
reset potentially call OpenGL functions without checking the context, and as
a result cause KWin to crash.

M  +1    -1    src/backends/drm/drm_egl_layer_surface.cpp
M  +1    -1    src/backends/drm/drm_virtual_egl_layer.cpp
M  +4    -3    src/backends/virtual/virtual_egl_backend.cpp
M  +1    -1    src/backends/wayland/wayland_egl_backend.cpp
M  +1    -1    src/backends/x11/x11_windowed_egl_backend.cpp
M  +1    -1    src/compositor.cpp
M  +2    -2    src/effect/offscreeneffect.cpp
M  +1    -1    src/effect/offscreenquickview.cpp
M  +4    -4    src/multigpuswapchain.cpp
M  +1    -1    src/opengl/eglcontext.cpp
M  +1    -1    src/opengl/eglcontext.h
M  +2    -2    src/opengl/glrendertimequery.cpp
M  +2    -4    src/plugins/qpa/eglplatformcontext.cpp
M  +4    -1    src/plugins/screencast/screencastbuffer.cpp
M  +4    -1    src/plugins/screencast/screencaststream.cpp
M  +1    -1    src/scene/opengl/atlas.cpp
M  +1    -1    src/scene/opengl/ninepatch.cpp
M  +3    -4    src/scripting/windowthumbnailitem.cpp

https://invent.kde.org/plasma/kwin/-/commit/6c523e20d1280b397d2437246ee86649fd8b0bbb

diff --git a/src/backends/drm/drm_egl_layer_surface.cpp b/src/backends/drm/drm_egl_layer_surface.cpp
index 49c39d2c5ac..a948b747a9c 100644
--- a/src/backends/drm/drm_egl_layer_surface.cpp
+++ b/src/backends/drm/drm_egl_layer_surface.cpp
@@ -64,7 +64,7 @@ EglGbmLayerSurface::Surface::~Surface()
 {
     importSwapchain.reset();
     if (context) {
-        context->makeCurrent();
+        (void)context->makeCurrent();
     }
 }
 
diff --git a/src/backends/drm/drm_virtual_egl_layer.cpp b/src/backends/drm/drm_virtual_egl_layer.cpp
index 7837f58ea80..7dbafac993c 100644
--- a/src/backends/drm/drm_virtual_egl_layer.cpp
+++ b/src/backends/drm/drm_virtual_egl_layer.cpp
@@ -141,7 +141,7 @@ bool VirtualEglGbmLayer::importScanoutBuffer(GraphicsBuffer *buffer, const std::
 
 void VirtualEglGbmLayer::releaseBuffers()
 {
-    m_eglBackend->openglContext()->makeCurrent();
+    (void)m_eglBackend->openglContext()->makeCurrent();
     m_gbmSwapchain.reset();
     m_oldGbmSwapchain.reset();
     m_currentSlot.reset();
diff --git a/src/backends/virtual/virtual_egl_backend.cpp b/src/backends/virtual/virtual_egl_backend.cpp
index 768a67faedb..97b729845f4 100644
--- a/src/backends/virtual/virtual_egl_backend.cpp
+++ b/src/backends/virtual/virtual_egl_backend.cpp
@@ -33,12 +33,14 @@ VirtualEglLayer::VirtualEglLayer(BackendOutput *output, VirtualEglBackend *backe
 
 VirtualEglLayer::~VirtualEglLayer()
 {
-    m_backend->openglContext()->makeCurrent();
+    (void)m_backend->openglContext()->makeCurrent();
 }
 
 std::optional<OutputLayerBeginFrameInfo> VirtualEglLayer::doBeginFrame()
 {
-    m_backend->openglContext()->makeCurrent();
+    if (!m_backend->openglContext()->makeCurrent()) {
+        return std::nullopt;
+    }
 
     const QSize nativeSize = m_output->modeSize();
     if (!m_swapchain || m_swapchain->size() != nativeSize) {
@@ -140,7 +142,6 @@ bool VirtualEglBackend::init()
 
 void VirtualEglBackend::addOutput(BackendOutput *output)
 {
-    openglContext()->makeCurrent();
     static_cast<VirtualOutput *>(output)->setOutputLayer(std::make_unique<VirtualEglLayer>(output, this));
 }
 
diff --git a/src/backends/wayland/wayland_egl_backend.cpp b/src/backends/wayland/wayland_egl_backend.cpp
index 378bac03160..0611b1b6765 100644
--- a/src/backends/wayland/wayland_egl_backend.cpp
+++ b/src/backends/wayland/wayland_egl_backend.cpp
@@ -153,7 +153,7 @@ WaylandEglCursorLayer::WaylandEglCursorLayer(WaylandOutput *output, WaylandEglBa
 
 WaylandEglCursorLayer::~WaylandEglCursorLayer()
 {
-    m_backend->openglContext()->makeCurrent();
+    (void)m_backend->openglContext()->makeCurrent();
 }
 
 std::optional<OutputLayerBeginFrameInfo> WaylandEglCursorLayer::doBeginFrame()
diff --git a/src/backends/x11/x11_windowed_egl_backend.cpp b/src/backends/x11/x11_windowed_egl_backend.cpp
index 7427df9fbaa..e0692bdd8dd 100644
--- a/src/backends/x11/x11_windowed_egl_backend.cpp
+++ b/src/backends/x11/x11_windowed_egl_backend.cpp
@@ -105,7 +105,7 @@ X11WindowedEglCursorLayer::X11WindowedEglCursorLayer(X11WindowedEglBackend *back
 
 X11WindowedEglCursorLayer::~X11WindowedEglCursorLayer()
 {
-    m_backend->openglContext()->makeCurrent();
+    (void)m_backend->openglContext()->makeCurrent();
     m_framebuffer.reset();
     m_texture.reset();
 }
diff --git a/src/compositor.cpp b/src/compositor.cpp
index ba756030cc4..16556798c8e 100644
--- a/src/compositor.cpp
+++ b/src/compositor.cpp
@@ -405,7 +405,7 @@ void Compositor::stop()
 
     if (m_backend->compositingType() == OpenGLCompositing) {
         // some layers need a context current for destruction
-        static_cast<EglBackend *>(m_backend.get())->openglContext()->makeCurrent();
+        (void)static_cast<EglBackend *>(m_backend.get())->openglContext()->makeCurrent();
     }
 
     const auto loops = m_primaryViews | std::views::transform([](const auto &pair) {
diff --git a/src/effect/offscreeneffect.cpp b/src/effect/offscreeneffect.cpp
index 8d2f18d9a50..a9d0698910e 100644
--- a/src/effect/offscreeneffect.cpp
+++ b/src/effect/offscreeneffect.cpp
@@ -86,7 +86,7 @@ void OffscreenEffect::unredirect(EffectWindow *window)
     }
 
     if (!EglContext::currentContext()) {
-        effects->openglContext()->makeCurrent();
+        (void)effects->openglContext()->makeCurrent();
     }
 
     d->windows.erase(it);
@@ -415,7 +415,7 @@ void CrossFadeEffect::unredirect(EffectWindow *window)
     }
 
     if (!EglContext::currentContext()) {
-        effects->openglContext()->makeCurrent();
+        (void)effects->openglContext()->makeCurrent();
     }
 
     d->windows.erase(it);
diff --git a/src/effect/offscreenquickview.cpp b/src/effect/offscreenquickview.cpp
index 30b322a859b..72dd363d5b1 100644
--- a/src/effect/offscreenquickview.cpp
+++ b/src/effect/offscreenquickview.cpp
@@ -399,7 +399,7 @@ void OffscreenQuickView::update(OutputFrame *frame)
         }
         d->m_glcontext->doneCurrent();
         if (previousContext) {
-            previousContext->makeCurrent();
+            (void)previousContext->makeCurrent();
         }
     }
     d->m_item->scheduleRepaint(d->m_item->rect());
diff --git a/src/multigpuswapchain.cpp b/src/multigpuswapchain.cpp
index 82219c77ace..4ab1fa0bcb2 100644
--- a/src/multigpuswapchain.cpp
+++ b/src/multigpuswapchain.cpp
@@ -97,7 +97,7 @@ std::unique_ptr<MultiGpuSwapchain> MultiGpuSwapchain::create(RenderDevice *copyD
         // creating the copy context will make it current
         const auto restoreContext = qScopeGuard([ctx = EglContext::currentContext()]() {
             if (ctx) {
-                ctx->makeCurrent();
+                (void)ctx->makeCurrent();
             }
         });
         const auto context = copyDevice->eglContext();
@@ -356,7 +356,7 @@ std::optional<MultiGpuSwapchain::Ret> MultiGpuSwapchain::copyWithEGL(GraphicsBuf
         if (previousContext) {
             // TODO make the calling code responsible for this?
             // If this makeCurrent fails, things might crash :/
-            previousContext->makeCurrent();
+            (void)previousContext->makeCurrent();
         }
     });
     if (!m_copyContext || m_copyContext->isFailed() || !m_copyContext->makeCurrent()) {
@@ -434,10 +434,10 @@ void MultiGpuSwapchain::deleteResources()
     if (m_copyContext) {
         const auto restoreContext = qScopeGuard([ctx = EglContext::currentContext()]() {
             if (ctx) {
-                ctx->makeCurrent();
+                (void)ctx->makeCurrent();
             }
         });
-        m_copyContext->makeCurrent();
+        (void)m_copyContext->makeCurrent();
         m_currentEglSlot.reset();
         m_eglSwapchain.reset();
         m_copyContext.reset();
diff --git a/src/opengl/eglcontext.cpp b/src/opengl/eglcontext.cpp
index 464da01ac23..e5c8e48ed73 100644
--- a/src/opengl/eglcontext.cpp
+++ b/src/opengl/eglcontext.cpp
@@ -114,7 +114,7 @@ EglContext::EglContext(EglDisplay *display, EGLConfig config, ::EGLContext conte
 
 EglContext::~EglContext()
 {
-    makeCurrent();
+    (void)makeCurrent();
     m_shaderManager.reset();
     m_streamingBuffer.reset();
     m_indexBuffer.reset();
diff --git a/src/opengl/eglcontext.h b/src/opengl/eglcontext.h
index 60b7b3999b5..e13bf6f1ef5 100644
--- a/src/opengl/eglcontext.h
+++ b/src/opengl/eglcontext.h
@@ -41,7 +41,7 @@ public:
     EglContext(EglDisplay *display, EGLConfig config, ::EGLContext context, EglContext *shareContext);
     ~EglContext();
 
-    bool makeCurrent();
+    [[nodiscard]] bool makeCurrent();
     bool makeCurrent(EGLSurface surface);
     void doneCurrent() const;
     std::shared_ptr<GLTexture> importDmaBufAsTexture(const DmaBufAttributes &attributes) const;
diff --git a/src/opengl/glrendertimequery.cpp b/src/opengl/glrendertimequery.cpp
index 438a97d8ba4..3e94dbebec2 100644
--- a/src/opengl/glrendertimequery.cpp
+++ b/src/opengl/glrendertimequery.cpp
@@ -39,7 +39,7 @@ GLRenderTimeQuery::~GLRenderTimeQuery()
     }
     glDeleteQueries(1, &m_gpuProbe.query);
     if (previousContext && previousContext != context.get()) {
-        previousContext->makeCurrent();
+        (void)previousContext->makeCurrent();
     }
 }
 
@@ -76,7 +76,7 @@ std::optional<RenderTimeSpan> GLRenderTimeQuery::query()
         glGetQueryObjecti64v(m_gpuProbe.query, GL_QUERY_RESULT, &end);
         m_gpuProbe.end = std::chrono::nanoseconds(end);
         if (previousContext && previousContext != context.get()) {
-            previousContext->makeCurrent();
+            (void)previousContext->makeCurrent();
         }
     }
 
diff --git a/src/plugins/qpa/eglplatformcontext.cpp b/src/plugins/qpa/eglplatformcontext.cpp
index b3736311afd..75386f3689d 100644
--- a/src/plugins/qpa/eglplatformcontext.cpp
+++ b/src/plugins/qpa/eglplatformcontext.cpp
@@ -53,7 +53,7 @@ EGLPlatformContext::~EGLPlatformContext()
         return;
     }
     if (!m_renderTargets.empty() || !m_zombieRenderTargets.empty()) {
-        m_eglContext->makeCurrent();
+        (void)m_eglContext->makeCurrent();
         m_renderTargets.clear();
         m_zombieRenderTargets.clear();
     }
@@ -202,8 +202,6 @@ void EGLPlatformContext::create(const QSurfaceFormat &format, EglContext *shareC
 
 void EGLPlatformContext::updateFormatFromContext()
 {
-    m_eglContext->makeCurrent();
-
     const char *version = reinterpret_cast<const char *>(glGetString(GL_VERSION));
     int major, minor;
     if (parseOpenGLVersion(version, major, minor)) {
@@ -260,7 +258,7 @@ void EGLPlatformContext::invalidateContext()
 {
     m_markedInvalid = true;
     if (m_eglContext) {
-        m_eglContext->makeCurrent();
+        (void)m_eglContext->makeCurrent();
         m_renderTargets.clear();
         m_zombieRenderTargets.clear();
         m_eglContext.reset();
diff --git a/src/plugins/screencast/screencastbuffer.cpp b/src/plugins/screencast/screencastbuffer.cpp
index 2bbe105ae11..fd2b9713839 100644
--- a/src/plugins/screencast/screencastbuffer.cpp
+++ b/src/plugins/screencast/screencastbuffer.cpp
@@ -57,7 +57,10 @@ DmaBufScreenCastBuffer *DmaBufScreenCastBuffer::create(pw_buffer *pwBuffer, cons
         return nullptr;
     }
 
-    backend->openglContext()->makeCurrent();
+    if (!backend->openglContext()->makeCurrent()) {
+        buffer->drop();
+        return nullptr;
+    }
 
     auto texture = backend->importDmaBufAsTexture(*attrs);
     if (!texture) {
diff --git a/src/plugins/screencast/screencaststream.cpp b/src/plugins/screencast/screencaststream.cpp
index 919e9c0039a..5a169e78d04 100644
--- a/src/plugins/screencast/screencaststream.cpp
+++ b/src/plugins/screencast/screencaststream.cpp
@@ -621,7 +621,10 @@ void ScreenCastStream::record(Contents contents)
     }
 
     EglContext *context = backend->openglContext();
-    context->makeCurrent();
+    if (!context->makeCurrent()) {
+        pw_stream_return_buffer(m_pwStream, pwBuffer);
+        return;
+    }
 
     spa_meta_sync_timeline *synctmeta = nullptr;
 
diff --git a/src/scene/opengl/atlas.cpp b/src/scene/opengl/atlas.cpp
index f179467cdfc..2926da0cd52 100644
--- a/src/scene/opengl/atlas.cpp
+++ b/src/scene/opengl/atlas.cpp
@@ -29,7 +29,7 @@ AtlasOpenGL::~AtlasOpenGL()
 {
     // FIXME: It should not be attached to the workspace scene.
     if (WorkspaceScene *scene = kwinApp()->scene()) {
-        scene->openglContext()->makeCurrent();
+        (void)scene->openglContext()->makeCurrent();
     }
 }
 
diff --git a/src/scene/opengl/ninepatch.cpp b/src/scene/opengl/ninepatch.cpp
index 1c040191a15..04de922974a 100644
--- a/src/scene/opengl/ninepatch.cpp
+++ b/src/scene/opengl/ninepatch.cpp
@@ -124,7 +124,7 @@ NinePatchOpenGL::NinePatchOpenGL(std::unique_ptr<GLTexture> &&texture)
 NinePatchOpenGL::~NinePatchOpenGL()
 {
     // FIXME: It should not be attached to the workspace scene.
-    kwinApp()->scene()->openglContext()->makeCurrent();
+    (void)kwinApp()->scene()->openglContext()->makeCurrent();
 }
 
 GLTexture *NinePatchOpenGL::texture() const
diff --git a/src/scripting/windowthumbnailitem.cpp b/src/scripting/windowthumbnailitem.cpp
index ee3ec441e24..b72c34d6fb7 100644
--- a/src/scripting/windowthumbnailitem.cpp
+++ b/src/scripting/windowthumbnailitem.cpp
@@ -65,13 +65,12 @@ WindowThumbnailSource::~WindowThumbnailSource()
     if (!m_offscreenTexture) {
         return;
     }
-    if (!QOpenGLContext::currentContext()) {
-        kwinApp()->scene()->openglContext()->makeCurrent();
-    }
+    const bool hasContext = QOpenGLContext::currentContext()
+        || kwinApp()->scene()->openglContext()->makeCurrent();
     m_offscreenTarget.reset();
     m_offscreenTexture.reset();
 
-    if (m_acquireFence) {
+    if (m_acquireFence && hasContext) {
         glDeleteSync(m_acquireFence);
         m_acquireFence = 0;
     }