[Fix] (DirectVulkan): build offscreen targets of a window-created renderer through AImageReader instead of a null headless entry point

MobileGL/MG_Backend/DirectVulkan/BackendObject_DirectVulkan.cpp

@@ -370,8 +370,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         const auto suspended = m_suspendedWindowSurfaces.find(m_activatingSurface);
         if (suspended != m_suspendedWindowSurfaces.end()) {
             if (UsesSurfaceTargets() && pVulkanRenderer) {
-                ActivateSuspendedPlaceholder(m_activatingSurface, suspended->second);
-                return true;
+                return ActivateSuspendedPlaceholder(m_activatingSurface, suspended->second);
             }
             return InitPbufferSurface(static_cast<EGLint>(suspended->second.Width),
                                       static_cast<EGLint>(suspended->second.Height));
@@ -386,8 +385,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         VulkanRendererConfig config;
         config.SwapInterval = GetRequestedSwapInterval();
         if (UsesSurfaceTargets() && pVulkanRenderer) {
-            pVulkanRenderer->ActivateSurfaceTarget(SurfaceTargetKey(m_activatingSurface), nativeWindow, config);
-            return true;
+            return pVulkanRenderer->ActivateSurfaceTarget(SurfaceTargetKey(m_activatingSurface), nativeWindow, config);
         }
         // Any renderer instance this assignment replaces is destroyed here;
         // fence/timer-query handles stamped with the old generation go stale.
@@ -404,8 +402,8 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         config.SurfaceWidth = static_cast<Uint32>(std::max<EGLint>(width, 1));
         config.SurfaceHeight = static_cast<Uint32>(std::max<EGLint>(height, 1));
         if (UsesSurfaceTargets() && pVulkanRenderer) {
-            pVulkanRenderer->ActivateSurfaceTarget(SurfaceTargetKey(m_activatingSurface), NativeWindowType{}, config);
-            return true;
+            return pVulkanRenderer->ActivateSurfaceTarget(SurfaceTargetKey(m_activatingSurface), NativeWindowType{},
+                                                          config);
         }
         // Any renderer instance this assignment replaces is destroyed here;
         // fence/timer-query handles stamped with the old generation go stale.
@@ -511,7 +509,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                 VulkanRendererConfig config;
                 config.SurfaceWidth = static_cast<Uint32>(state->Width);
                 config.SurfaceHeight = static_cast<Uint32>(state->Height);
-                pVulkanRenderer->ActivateSurfaceTarget(SurfaceTargetKey(surface), NativeWindowType{}, config);
+                (void)pVulkanRenderer->ActivateSurfaceTarget(SurfaceTargetKey(surface), NativeWindowType{}, config);
             }
             return true;
         }
@@ -610,7 +608,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         BackendObject::ReleaseEGLResources();
     }
 
-    void BackendObject_DirectVulkan::ActivateSuspendedPlaceholder(EGLSurface surface,
+    Bool BackendObject_DirectVulkan::ActivateSuspendedPlaceholder(EGLSurface surface,
                                                                   const SuspendedWindowSurface& extent) {
         // A pbuffer target at the window's extent: every default-framebuffer path (render passes,
         // read-back, the shared-image blit, the acquire and the present) keeps a live swapchain to
@@ -618,7 +616,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         VulkanRendererConfig config;
         config.SurfaceWidth = std::max<Uint32>(extent.Width, 1);
         config.SurfaceHeight = std::max<Uint32>(extent.Height, 1);
-        pVulkanRenderer->ActivateSurfaceTarget(SurfaceTargetKey(surface), NativeWindowType{}, config);
+        return pVulkanRenderer->ActivateSurfaceTarget(SurfaceTargetKey(surface), NativeWindowType{}, config);
     }
 
     Bool BackendObject_DirectVulkan::SuspendServerWindow(void* window) {
@@ -648,7 +646,9 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                 // swapchain and VkSurfaceKHR - nothing references the window after this.
                 pVulkanRenderer->DestroySurfaceTarget(key);
                 m_suspendedWindowSurfaces[client] = extent;
-                if (active) ActivateSuspendedPlaceholder(client, extent);
+                // A placeholder that cannot be built is a suspend that failed: the window is already let
+                // go of, and the caller ends the session by name instead (its EGL resources go).
+                if (active && !ActivateSuspendedPlaceholder(client, extent)) return false;
             } else {
                 m_suspendedWindowSurfaces[client] = extent;
             }
@@ -686,7 +686,9 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             config.SurfaceWidth = std::max<Uint32>(width, 1);
             config.SurfaceHeight = std::max<Uint32>(height, 1);
             config.SwapInterval = GetRequestedSwapInterval();
-            pVulkanRenderer->ActivateSurfaceTarget(key, reinterpret_cast<NativeWindowType>(window), config);
+            if (!pVulkanRenderer->ActivateSurfaceTarget(key, reinterpret_cast<NativeWindowType>(window), config)) {
+                return false;
+            }
         }
         MGLOG_I("DirectVulkan: %zu suspended window surface(s) rebuilt on server window %p (%ux%u)", suspended.size(),
                 window, width, height);

MobileGL/MG_Backend/DirectVulkan/BackendObject_DirectVulkan.h

@@ -81,8 +81,8 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             Uint32 Height = 1;
         };
         UnorderedMap<EGLSurface, SuspendedWindowSurface> m_suspendedWindowSurfaces;
-        // The placeholder pbuffer target of a suspended surface, made active.
-        void ActivateSuspendedPlaceholder(EGLSurface surface, const SuspendedWindowSurface& extent);
+        // The placeholder pbuffer target of a suspended surface, made active. False: it could not be built.
+        Bool ActivateSuspendedPlaceholder(EGLSurface surface, const SuspendedWindowSurface& extent);
     };
 
     // Single-source-of-truth helpers shared with the driver POST

MobileGL/MG_Backend/DirectVulkan/Renderer/OffscreenSurfaceRoute.h

@@ -0,0 +1,37 @@
+// MobileGL - MobileGL/MG_Backend/DirectVulkan/Renderer/OffscreenSurfaceRoute.h
+// Copyright (c) 2025-2026 MobileGL-Dev
+// Licensed under the GNU Lesser General Public License v3.0:
+//   https://www.gnu.org/licenses/gpl-3.0.txt
+//   https://www.gnu.org/licenses/lgpl-3.0.txt
+// SPDX-License-Identifier: LGPL-3.0-only
+// End of Source File Header
+
+// How an offscreen (pbuffer) surface target gets its VkSurfaceKHR on Android, decided from what the
+// INSTANCE has, not from what the loader could offer. A renderer created for a window enabled
+// VK_KHR_android_surface and nothing headless, so its later offscreen targets (a second client
+// surface, or the placeholder a suspended server window draws into) must take the AImageReader
+// route; asking that instance for vkCreateHeadlessSurfaceEXT answers null. Pure, so a host case pins
+// it without a driver.
+
+#pragma once
+#include <Includes.h>
+
+namespace MobileGL::MG_Backend::DirectVulkan {
+
+    enum class OffscreenSurfaceRoute : Uint8 {
+        Headless,           // vkCreateHeadlessSurfaceEXT
+        AndroidImageReader, // vkCreateAndroidSurfaceKHR on an AImageReader's window nobody displays
+        Unavailable,        // neither: the target cannot be built (the caller refuses, by name)
+    };
+
+    // `headlessEnabled`: the instance was created with VK_EXT_headless_surface.
+    // `headlessEntryPoint`: vkGetInstanceProcAddr answered vkCreateHeadlessSurfaceEXT.
+    // `androidSurfaceEnabled`: the instance was created with VK_KHR_android_surface.
+    constexpr OffscreenSurfaceRoute ChooseOffscreenSurfaceRoute(Bool headlessEnabled, Bool headlessEntryPoint,
+                                                                Bool androidSurfaceEnabled) {
+        if (headlessEnabled && headlessEntryPoint) return OffscreenSurfaceRoute::Headless;
+        if (androidSurfaceEnabled) return OffscreenSurfaceRoute::AndroidImageReader;
+        return OffscreenSurfaceRoute::Unavailable;
+    }
+
+} // namespace MobileGL::MG_Backend::DirectVulkan

MobileGL/MG_Backend/DirectVulkan/Renderer/VulkanRenderer.cpp

@@ -8,6 +8,7 @@
 
 #include "VulkanRenderer.h"
 #include "SubmitFencePrefix.h"
+#include "OffscreenSurfaceRoute.h"
 
 #include "MG_Backend/DirectVulkan/SubgroupSupportPolicy.h"
 #include "MG_Backend/DirectGLES/Utils.h"
@@ -3267,7 +3268,7 @@ void main() {
         MagmaPipeValidateSubsystemConfiguration();
 #endif
         CreateInstance();
-        CreateSurface();
+        if (!CreateSurface()) throw RuntimeError("DirectVulkan: the initial surface could not be created");
         PickPhysicalDevice();
         CreateLogicalDeviceAndQueues();
         CreateAllocator();
@@ -14807,6 +14808,7 @@ void main() {
                 MGLOG_I("%s not available; falling back to an AImageReader %s surface for the pbuffer context.",
                         VK_EXT_HEADLESS_SURFACE_EXTENSION_NAME, VK_KHR_ANDROID_SURFACE_EXTENSION_NAME);
                 exts.push_back(VK_KHR_ANDROID_SURFACE_EXTENSION_NAME);
+                m_androidSurfaceEnabled = true;
             }
 #elif defined VK_USE_PLATFORM_XLIB_KHR
             // An offscreen surface has ZERO window-system dependence, by design and on
@@ -14833,6 +14835,7 @@ void main() {
         } else {
 #ifdef VK_USE_PLATFORM_ANDROID_KHR
             exts.push_back(VK_KHR_ANDROID_SURFACE_EXTENSION_NAME);
+            m_androidSurfaceEnabled = true;
 #elif defined VK_USE_PLATFORM_WIN32_KHR
             exts.push_back(VK_KHR_WIN32_SURFACE_EXTENSION_NAME);
 #elif defined VK_USE_PLATFORM_METAL_EXT
@@ -16438,42 +16441,66 @@ void main() {
         MGLOG_I("Command pool created");
     }
 
-    void VulkanRenderer::CreateSurface() {
+    Bool VulkanRenderer::CreateSurface() {
         if (!m_window) {
 #if defined VK_USE_PLATFORM_METAL_EXT
             m_window = reinterpret_cast<NativeWindowType>(
                 CreateInternalMetalLayer(m_config.SurfaceWidth, m_config.SurfaceHeight, &m_platformDisplay));
             m_platformLibrary = reinterpret_cast<void*>(m_window);
 #elif defined VK_USE_PLATFORM_ANDROID_KHR
-            if (m_headlessSurfaceSupported) {
-                auto* createHeadlessSurface = reinterpret_cast<PFN_vkCreateHeadlessSurfaceEXT>(
-                    vkGetInstanceProcAddr(m_instance, "vkCreateHeadlessSurfaceEXT"));
-                MOBILEGL_ASSERT(createHeadlessSurface != nullptr,
-                                "VK_EXT_headless_surface is not available for DirectVulkan pbuffer surface");
+            // EVERY ENTRY POINT HERE IS OPTIONAL, and each refusal is a `return false`, not
+            // MOBILEGL_ASSERT: that macro is compiled out at the INFO level every shipping build uses,
+            // and a renderer created for a WINDOW never enabled the headless extension - asking its
+            // instance for vkCreateHeadlessSurfaceEXT answers null, and calling that crashed the server
+            // the first time such a renderer needed an offscreen target.
+            auto* createHeadlessSurface =
+                m_headlessSurfaceSupported ? reinterpret_cast<PFN_vkCreateHeadlessSurfaceEXT>(
+                                                 vkGetInstanceProcAddr(m_instance, "vkCreateHeadlessSurfaceEXT"))
+                                           : nullptr;
+            const OffscreenSurfaceRoute route = ChooseOffscreenSurfaceRoute(
+                m_headlessSurfaceSupported, createHeadlessSurface != nullptr, m_androidSurfaceEnabled);
+            if (route == OffscreenSurfaceRoute::Headless) {
                 VkHeadlessSurfaceCreateInfoEXT sci{VK_STRUCTURE_TYPE_HEADLESS_SURFACE_CREATE_INFO_EXT};
-                VK_VERIFY(createHeadlessSurface(m_instance, &sci, nullptr, &m_surface),
-                          "vkCreateHeadlessSurfaceEXT failed");
-                return;
+                const VkResult result = createHeadlessSurface(m_instance, &sci, nullptr, &m_surface);
+                if (result != VK_SUCCESS) {
+                    MGLOG_E("DirectVulkan: vkCreateHeadlessSurfaceEXT failed (%d) for an offscreen target",
+                            static_cast<int>(result));
+                    m_surface = VK_NULL_HANDLE;
+                    return false;
+                }
+                return true;
+            }
+            if (route == OffscreenSurfaceRoute::Unavailable) {
+                MGLOG_E("DirectVulkan: no offscreen surface route on this instance (neither %s nor %s enabled)",
+                        VK_EXT_HEADLESS_SURFACE_EXTENSION_NAME, VK_KHR_ANDROID_SURFACE_EXTENSION_NAME);
+                return false;
             }
             // Windowless context on a driver without VK_EXT_headless_surface: give
             // the WSI an AImageReader's ANativeWindow. It is a real, valid producer
             // surface that is attached to no display and whose images this code never
             // acquires, which is exactly the "drawable nobody sees" the Xlib fallback
             // below builds out of an unmapped window. libmediandk is dlopen'd rather
-            // than linked so a device without it degrades to the old error instead of
+            // than linked so a device without it degrades to a refusal instead of
             // failing to load the library at all.
             {
                 void* mediaLib = dlopen("libmediandk.so", RTLD_NOW | RTLD_LOCAL);
-                MOBILEGL_ASSERT(mediaLib != nullptr,
-                                "VK_EXT_headless_surface is unavailable and libmediandk.so could not be loaded "
-                                "for the pbuffer surface fallback");
+                if (mediaLib == nullptr) {
+                    MGLOG_E("DirectVulkan: libmediandk.so could not be loaded for an offscreen target");
+                    return false;
+                }
                 using AImageReaderNewFn = int (*)(int32_t, int32_t, int32_t, int32_t, void**);
                 using AImageReaderGetWindowFn = int (*)(void*, void**);
+                using AImageReaderDeleteFn = void (*)(void*);
                 auto* imageReaderNew = reinterpret_cast<AImageReaderNewFn>(dlsym(mediaLib, "AImageReader_new"));
                 auto* imageReaderGetWindow =
                     reinterpret_cast<AImageReaderGetWindowFn>(dlsym(mediaLib, "AImageReader_getWindow"));
-                MOBILEGL_ASSERT(imageReaderNew != nullptr && imageReaderGetWindow != nullptr,
-                                "libmediandk.so is missing AImageReader_new/AImageReader_getWindow");
+                auto* imageReaderDelete =
+                    reinterpret_cast<AImageReaderDeleteFn>(dlsym(mediaLib, "AImageReader_delete"));
+                if (imageReaderNew == nullptr || imageReaderGetWindow == nullptr || imageReaderDelete == nullptr) {
+                    MGLOG_E("DirectVulkan: libmediandk.so is missing AImageReader_new/getWindow/delete");
+                    dlclose(mediaLib);
+                    return false;
+                }
 
                 constexpr int32_t kAndroidFormatRgba8888 = 0x1; // AIMAGE_FORMAT_RGBA_8888
                 const int32_t width = static_cast<int32_t>(std::max<Uint32>(m_config.SurfaceWidth, 1));
@@ -16482,12 +16509,16 @@ void main() {
                 // maxImages must cover the swapchain's images; the reader never
                 // acquires any, so this only sizes its buffer queue.
                 const int status = imageReaderNew(width, height, kAndroidFormatRgba8888, 8, &reader);
-                MOBILEGL_ASSERT(status == 0 && reader != nullptr,
-                                "AImageReader_new failed (%d) for the pbuffer surface fallback", status);
                 void* nativeWindow = nullptr;
-                const int windowStatus = imageReaderGetWindow(reader, &nativeWindow);
-                MOBILEGL_ASSERT(windowStatus == 0 && nativeWindow != nullptr,
-                                "AImageReader_getWindow failed (%d) for the pbuffer surface fallback", windowStatus);
+                const int windowStatus =
+                    (status == 0 && reader != nullptr) ? imageReaderGetWindow(reader, &nativeWindow) : -1;
+                if (windowStatus != 0 || nativeWindow == nullptr) {
+                    MGLOG_E("DirectVulkan: no AImageReader window for an offscreen target (new %d, getWindow %d)",
+                            status, windowStatus);
+                    if (reader != nullptr) imageReaderDelete(reader);
+                    dlclose(mediaLib);
+                    return false;
+                }
                 m_fallbackImageReader = reader;
                 m_platformLibrary = mediaLib;
                 m_window = reinterpret_cast<NativeWindowType>(nativeWindow);
@@ -16510,7 +16541,7 @@ void main() {
             VkHeadlessSurfaceCreateInfoEXT sci{VK_STRUCTURE_TYPE_HEADLESS_SURFACE_CREATE_INFO_EXT};
             VK_VERIFY(createHeadlessSurface(m_instance, &sci, nullptr, &m_surface),
                       "vkCreateHeadlessSurfaceEXT failed");
-            return;
+            return true;
 #else
             auto* createHeadlessSurface =
                 reinterpret_cast<PFN_vkCreateHeadlessSurfaceEXT>(
@@ -16526,7 +16557,7 @@ void main() {
             VkHeadlessSurfaceCreateInfoEXT sci{VK_STRUCTURE_TYPE_HEADLESS_SURFACE_CREATE_INFO_EXT};
             VK_VERIFY(createHeadlessSurface(m_instance, &sci, nullptr, &m_surface),
                       "vkCreateHeadlessSurfaceEXT failed");
-            return;
+            return true;
 #endif
         }
 #if defined VK_USE_PLATFORM_ANDROID_KHR
@@ -16535,7 +16566,12 @@ void main() {
 
         VkAndroidSurfaceCreateInfoKHR sci{VK_STRUCTURE_TYPE_ANDROID_SURFACE_CREATE_INFO_KHR};
         sci.window = nativeWindow;
-        VK_VERIFY(vkCreateAndroidSurfaceKHR(m_instance, &sci, nullptr, &m_surface), "vkCreateAndroidSurfaceKHR failed");
+        const VkResult androidSurfaceResult = vkCreateAndroidSurfaceKHR(m_instance, &sci, nullptr, &m_surface);
+        if (androidSurfaceResult != VK_SUCCESS) {
+            MGLOG_E("DirectVulkan: vkCreateAndroidSurfaceKHR failed (%d)", static_cast<int>(androidSurfaceResult));
+            m_surface = VK_NULL_HANDLE;
+            return false;
+        }
 #elif defined VK_USE_PLATFORM_WIN32_KHR
         auto hwnd = static_cast<HWND>(m_window);
         MOBILEGL_ASSERT(hwnd, "HWND is null");
@@ -16606,6 +16642,7 @@ void main() {
         MGLOG_W("VulkanRenderer::Initialize called on a platform which is not supported yet"); // TODO: support more
                                                                                                // platforms
 #endif
+        return true;
     }
 
     Vector<VkQueueFamilyProperties> VulkanRenderer::GetQueueFamilyFromPhysicalDevice(VkPhysicalDevice device) {
@@ -16947,9 +16984,9 @@ void main() {
         InvalidateSetupDrawSnapshots();
     }
 
-    void VulkanRenderer::ActivateSurfaceTarget(Uint64 key, NativeWindowType window,
+    Bool VulkanRenderer::ActivateSurfaceTarget(Uint64 key, NativeWindowType window,
                                                const VulkanRendererConfig& surfaceConfig) {
-        if (key == m_activeTargetKey && m_surface != VK_NULL_HANDLE) return;
+        if (key == m_activeTargetKey && m_surface != VK_NULL_HANDLE) return true;
         ParkActiveTarget();
         auto parked = m_parkedTargets.find(key);
         if (parked != m_parkedTargets.end()) {
@@ -16967,7 +17004,17 @@ void main() {
             m_swapchainSwapInterval.reset();
             m_swapchainResizeRequested = false;
             m_presentSuspended = false;
-            CreateSurface();
+            if (!CreateSurface()) {
+                // Nothing of the half-built target stays active: its image reader and library go
+                // with it, and the renderer has no target until the caller activates another.
+                SurfaceTarget failed;
+                ExchangeActiveTarget(failed);
+                DestroyParkedTarget(failed);
+                m_activeTargetKey = 0;
+                MGLOG_E("DirectVulkan: surface target for key %llu could not be built (%s)",
+                        static_cast<unsigned long long>(key), window != NativeWindowType{} ? "window" : "pbuffer");
+                return false;
+            }
             CreateSwapchain();
             m_defaultFramebufferImageIndex = 0;
             VK_VERIFY(m_frameContext.InitializeSwapchainSemaphores(
@@ -16988,6 +17035,7 @@ void main() {
         }
         m_activeTargetKey = key;
         OnActiveTargetChanged();
+        return true;
     }
 
     void VulkanRenderer::DestroyParkedTarget(SurfaceTarget& target) {

MobileGL/MG_Backend/DirectVulkan/Renderer/VulkanRenderer.h

@@ -453,7 +453,9 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         // Activating another key parks the active target - its recorded work submitted, its
         // pending acquire consumed - and brings the other back, or builds it on first use.
         void SetActiveSurfaceTargetKey(Uint64 key) { m_activeTargetKey = key; }
-        void ActivateSurfaceTarget(Uint64 key, NativeWindowType window, const VulkanRendererConfig& surfaceConfig);
+        // False when a NEW target's surface could not be built (logged); the renderer is then left
+        // with no active target - every present drops its frame - and the caller refuses by name.
+        Bool ActivateSurfaceTarget(Uint64 key, NativeWindowType window, const VulkanRendererConfig& surfaceConfig);
         // Drops a surface's target, active or parked. A no-op for a key that has none.
         void DestroySurfaceTarget(Uint64 key);
         // The default framebuffer's extent (surface space, what PublishDefaultFramebufferInfo
@@ -944,7 +946,12 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         // a substituted window. (Android is the one exception and has its own path -
         // no Mali/Adreno driver seen so far exposes the extension, so a windowless
         // context is given an AImageReader ANativeWindow that is never displayed.)
-        Bool m_headlessSurfaceSupported = true;
+        // ENABLED ON THIS INSTANCE, not merely offered: a renderer created for a window never asks
+        // for the extension, and its later offscreen targets must not call an entry point the
+        // instance does not have (OffscreenSurfaceRoute.h). Hence false until CreateInstance says so.
+        Bool m_headlessSurfaceSupported = false;
+        // VK_KHR_android_surface was enabled on this instance (the AImageReader route needs it).
+        Bool m_androidSurfaceEnabled = false;
         // Android has the same shortfall: no Mali/Adreno driver seen so far exposes
         // VK_EXT_headless_surface, so a windowless (EGL pbuffer) context gets an
         // AImageReader's ANativeWindow to hand the WSI instead. Nothing is ever
@@ -1963,7 +1970,8 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         VkResult SetupDebugReportCallback();
         void DestroyDebugReportCallback();
         VkDebugUtilsMessengerCreateInfoEXT PopulateDebugMessengerCreateInfo();
-        void CreateSurface();
+        // False (logged) when the target's surface cannot be built; the renderer then has no surface.
+        Bool CreateSurface();
         void PickPhysicalDevice();
         void CreateLogicalDeviceAndQueues();
         void CreateAllocator();

MobileGL/MG_Test/Wire/ServerLoopTest.cpp

@@ -38,6 +38,7 @@
 #include <MG_Backend/DirectGLES/Utils.h>
 #include <MG_Backend/MGPipe/PipeInputs.h>
 #include <MG_Backend/DirectVulkan/Renderer/VulkanRenderer.h>
+#include <MG_Backend/DirectVulkan/Renderer/OffscreenSurfaceRoute.h>
 #include <MG_Impl/Pipe/PipeFill.h>
 #include <MG_Impl/Pipe/ResourceTracker.h>
 #include <MG_Pipe/MGPipe.h>
@@ -3733,6 +3734,30 @@ TEST(ServerLoopSuspendTest, ABackendThatCannotSuspendStillLatchesServerWindowLos
 
 // Mid-stream: answered within the stream (DrainRing's per-pop check) and the stream goes on. Red with
 // the suspend arm deleted: the stream is cut at the latch (bits 4|8|16).
+// MAGMA'S PLACEHOLDER ON A RENDERER CREATED FOR A WINDOW (the device crash: SIGSEGV at pc 0 in
+// VulkanRenderer::CreateSurface on screen-off). The on-screen session's renderer was built for the
+// server's window, so its instance enabled the Android surface extension and nothing headless; the
+// suspend's offscreen placeholder must take the AImageReader route - the way a windowless renderer's
+// pbuffers are built on drivers without the headless extension - and never call a headless entry point
+// the instance does not have. With no route at all the target is refused (and the suspend fails, so the
+// session latches as the cannot-suspend case below shows) instead of called through a null pointer.
+// Red with the route keyed on what the LOADER offers rather than what the instance enabled (the first
+// two expectations answer Headless).
+TEST(ServerLoopSuspendTest, AnOffscreenTargetNeverCallsAHeadlessEntryPointTheInstanceDoesNotHave) {
+    using MG_Backend::DirectVulkan::ChooseOffscreenSurfaceRoute;
+    using MG_Backend::DirectVulkan::OffscreenSurfaceRoute;
+    // A renderer created for a window: Android surfaces enabled, the headless extension never enabled -
+    // whether or not the loader would answer its entry point.
+    EXPECT_EQ(ChooseOffscreenSurfaceRoute(false, false, true), OffscreenSurfaceRoute::AndroidImageReader);
+    EXPECT_EQ(ChooseOffscreenSurfaceRoute(false, true, true), OffscreenSurfaceRoute::AndroidImageReader);
+    // Enabled, but the entry point is absent: still never called.
+    EXPECT_EQ(ChooseOffscreenSurfaceRoute(true, false, true), OffscreenSurfaceRoute::AndroidImageReader);
+    EXPECT_EQ(ChooseOffscreenSurfaceRoute(true, false, false), OffscreenSurfaceRoute::Unavailable);
+    EXPECT_EQ(ChooseOffscreenSurfaceRoute(false, false, false), OffscreenSurfaceRoute::Unavailable);
+    // A windowless renderer on a driver that has the extension.
+    EXPECT_EQ(ChooseOffscreenSurfaceRoute(true, true, false), OffscreenSurfaceRoute::Headless);
+}
+
 TEST(ServerLoopSuspendTest, ALostServerWindowMidStreamSuspendsPromptlyAndTheStreamCarriesOn) {
     EXPECT_EXIT(SuspendMidStreamAndExit(), ::testing::ExitedWithCode(0), ".*")
         << "bits: 1 = Detach did not answer ReleasedBySession; 2 = Detach took 1 s or more; 4 = the stream was "