Disable QPlatformIntegration::Capability::OpenGL on macOS 26 in VMsHEADdev

Or rather, when detecting that the software GL renderer is in use,
which is the case in VMs, or when requesting Qt::AA_UseSoftwareOpenGL
explictly.

In this situation macOS 26 crashes in [NSOpenGLContext flushBuffer]
and [NSOpenGLContext setView:], making it unusable.

Hopefully this issue is resolved in the platform, but for now we
report lack of OpenGL so we can get our tests passing/skipping in CI.

Change-Id: I68412aed5174194c80d2b079ffba141f9f2a3be1
Reviewed-by: Volker Hilsheimer <[email protected]>

3 files changed, 29 insertions, 0 deletions

diff --git a/src/plugins/platforms/cocoa/qcocoaglcontext.h b/src/plugins/platforms/cocoa/qcocoaglcontext.h
index 36546879ae4..13139dd399d 100644
--- a/src/plugins/platforms/cocoa/qcocoaglcontext.h
+++ b/src/plugins/platforms/cocoa/qcocoaglcontext.h
@@ -43,6 +43,8 @@ public:
 
     QFunctionPointer getProcAddress(const char *procName) override;
 
+    bool isSoftwareContext() const;
+
 private:
     static NSOpenGLPixelFormat *pixelFormatForSurfaceFormat(const QSurfaceFormat &format);
 
@@ -54,6 +56,7 @@ private:
     QSurfaceFormat m_format;
     QVarLengthArray<QMacNotificationObserver, 3> m_updateObservers;
     QAtomicInt m_needsUpdate = false;
+    bool m_isSoftwareContext = false;
 
 #ifndef QT_NO_DEBUG_STREAM
     friend QDebug operator<<(QDebug debug, const QCocoaGLContext *screen);
diff --git a/src/plugins/platforms/cocoa/qcocoaglcontext.mm b/src/plugins/platforms/cocoa/qcocoaglcontext.mm
index bfac716b633..2f0f513dfc1 100644
--- a/src/plugins/platforms/cocoa/qcocoaglcontext.mm
+++ b/src/plugins/platforms/cocoa/qcocoaglcontext.mm
@@ -289,6 +289,9 @@ void QCocoaGLContext::updateSurfaceFormat()
     else
         m_format.setSwapBehavior(QSurfaceFormat::SingleBuffer);
 
+    m_isSoftwareContext = (pixelFormatAttribute(NSOpenGLPFARendererID)
+        & kCGLRendererIDMatchingMask) == kCGLRendererGenericFloatID;
+
     // ------------------- Query the context -------------------
 
     auto glContextParameter = [&](NSOpenGLContextParameter parameter) {
@@ -512,6 +515,11 @@ bool QCocoaGLContext::isSharing() const
     return m_shareContext != nil;
 }
 
+bool QCocoaGLContext::isSoftwareContext() const
+{
+    return m_isSoftwareContext;
+}
+
 NSOpenGLContext *QCocoaGLContext::nativeContext() const
 {
     return m_context;
diff --git a/src/plugins/platforms/cocoa/qcocoaintegration.mm b/src/plugins/platforms/cocoa/qcocoaintegration.mm
index 8c6dcfd4f60..4c5975af34a 100644
--- a/src/plugins/platforms/cocoa/qcocoaintegration.mm
+++ b/src/plugins/platforms/cocoa/qcocoaintegration.mm
@@ -232,6 +232,24 @@ bool QCocoaIntegration::hasCapability(QPlatformIntegration::Capability cap) cons
         // layer-backed.
         return false;
     case OpenGL:
+        if (QOperatingSystemVersion::current() > QOperatingSystemVersion::MacOSSonoma) {
+            // Tahoe has issues with software-backed GL, crashing in common operations
+            static bool isSoftwareContext = []{
+                QOpenGLContext context;
+                context.create();
+                auto *cocoaContext = static_cast<QCocoaGLContext*>(context.handle());
+                if (cocoaContext->isSoftwareContext()) {
+                    qWarning() << "Detected software OpenGL backend,"
+                        << "which is known to be broken on"
+                        << qUtf8Printable(QSysInfo::prettyProductName());
+                    return true;
+                } else {
+                    return false;
+                }
+            }();
+            return !isSoftwareContext;
+        }
+        Q_FALLTHROUGH();
     case BufferQueueingOpenGL:
 #endif
     case ThreadedPixmaps: