fix: use WEBKIT_DISABLE_DMABUF_RENDERER 1 when using WebKitGTK >= 2.46

.claude/skills/orca-wxwidgets/references/webview-gl-aui-media.md

@@ -61,8 +61,10 @@ available; GTK2/WebKit1 is an opt-out configuration the GUI does not support.
 11. A web host that re-themes in place handles `EVT_WEBVIEW_RECREATED` without `Skip()`; one that
     needs a reload lets it through. §[Orca wrapper](#orca-webview-wrapper-widgetswebview)
 12. Keep `WebViewWebKit`'s destructor removing the `"wx"` handler. §[Orca wrapper](#orca-webview-wrapper-widgetswebview)
-13. Do not widen `WEBKIT_DISABLE_COMPOSITING_MODE` beyond Orca's default-path XWayland case, and never
-    make a page's progress depend only on a C++→JS callback. §[WebKitGTK on Linux](#webkitgtk-on-linux-sessions)
+13. Do not widen `WEBKIT_DISABLE_COMPOSITING_MODE` beyond Orca's default-path XWayland case. Disable the
+    WebKit DMA-BUF renderer only for the NVIDIA proprietary driver on native Wayland (GNOME/gtk#8056), and
+    never make a page's progress depend only on a C++→JS callback.
+    §[WebKitGTK on Linux](#webkitgtk-on-linux-sessions)
 14. GL attribute lists: legacy `int[]` lists end with `0` and spell out `WX_GL_RGBA` and
     `WX_GL_DOUBLEBUFFER`; `wxGLAttributes`/`wxGLContextAttrs` end with `EndList()`; MSAA is requested
     explicitly. §[wxGLCanvas](#wxglcanvas-and-wxglcontext)
@@ -599,6 +601,25 @@ Runtime backend detection elsewhere uses Orca's `is_running_on_wayland()` / `is_
   Cite: c12912e0df (`src/OrcaSlicer.cpp`; `resources/web/guide/0/load.js` `OnInit`
   `setTimeout("JumpToTarget()", …)`), 9446030079 (the `GDK_BACKEND=x11` opt-in branch).
 
+**DMA-BUF renderer / explicit sync (NVIDIA + Wayland).**
+- **Rule:** On the Wayland default path, set `WEBKIT_DISABLE_DMABUF_RENDERER=1` non-replacing, gated to
+  `__linux__` + native Wayland (not the forced-X11 fallback) + `/proc/driver/nvidia/version` +
+  `WebView::WebKitAtLeast(2, 46)`. The version gate uses the runtime `webkit_get_major_version()` /
+  `webkit_get_minor_version()` getters (no GTK init needed), not a compile-time macro, and 2.46 is the
+  oldest release with a confirmed crash report — narrower gates (e.g. 2.54) would miss 2.46–2.52 victims.
+  **Why:** WebKitGTK's DMA-BUF renderer arms `linux-drm-syncobj-v1` on the toplevel surface; GTK3 then
+  commits its first shared-memory frame without an acquire point, and KWin/Mutter reject the commit with
+  `Error 71 (Protocol error)` — GDK turns that into `_exit(1)` before Orca logs anything. The defect is
+  GTK3's `gdk_wayland_window_attach_image()` (GNOME/gtk#8056); WebKit only triggers it, the NVIDIA
+  proprietary driver has no implicit-sync fallback (Mesa tolerates it), and no upstream fix or PR exists.
+  This is a different variable from `WEBKIT_DISABLE_COMPOSITING_MODE` and does not replace it.
+  ```cpp
+  // Wayland default path, before GTK init
+  if (!x11_backend && wayland && ::access("/proc/driver/nvidia/version", F_OK) == 0 &&
+      WebView::WebKitAtLeast(2, 46))
+      ::setenv("WEBKIT_DISABLE_DMABUF_RENDERER", "1", /* replace */ false);
+  ```
+
 ## wxGLCanvas and wxGLContext
 
 **Attributes.**

src/OrcaSlicer.cpp

@@ -165,6 +165,7 @@ using json = nlohmann::json;
 
 #ifdef SLIC3R_GUI
     #include "slic3r/GUI/GUI_Init.hpp"
+    #include "slic3r/GUI/Widgets/WebView.hpp"
     // BBLPrinterAgent::from_orca_filament_id(); the map and its lookups live in libslic3r_gui,
     // which only a SLIC3R_GUI build links (see target_link_libraries(OrcaSlicer libslic3r_gui)
     // in CMakeLists).
@@ -1155,6 +1156,12 @@ int CLI::run(int argc, char **argv)
     // unset preserves WebKit hardware acceleration on Device / Setup
     // Wizard / login / store. The default path still applies it on
     // XWayland sessions as a conservative fallback for older WebKit.
+    //
+    // The default path also disables WebKit's DMA-BUF renderer when the
+    // NVIDIA proprietary driver is in use on native Wayland. That is a
+    // separate switch from compositing and is needed because GTK3 commits
+    // a shared-memory frame onto an explicit-sync surface (GNOME/gtk#8056),
+    // which KWin/Mutter reject with "Error 71 (Protocol error)".
     // ------------------------------------------------------------------
     {
         const char* gdk_backend = ::getenv("GDK_BACKEND");
@@ -1218,6 +1225,34 @@ int CLI::run(int argc, char **argv)
                 }
             }
 
+            // WebKitGTK's DMA-BUF renderer arms explicit sync
+            // (linux-drm-syncobj-v1) on the toplevel Wayland surface. If the
+            // first painted frame is a shared-memory buffer, GTK3's
+            // gdk_wayland_window_attach_image() commits it without an acquire
+            // point, and compositors that enforce the protocol (KWin, Mutter)
+            // terminate the client with "Error 71 (Protocol error)" before the
+            // app can log anything (GNOME/gtk#8056). NVIDIA's proprietary
+            // driver has no implicit-sync fallback, so the crash only happens
+            // there; Mesa tolerates the missing point. Scope the workaround to
+            // NVIDIA on native Wayland, on WebKitGTK >= 2.46 (the oldest release
+            // with a confirmed report; the DMA-BUF renderer predates it).
+            // Non-replacing, so a user who does not hit the bug can opt back in
+            // with WEBKIT_DISABLE_DMABUF_RENDERER=0.
+            #if defined(__linux__)
+            {
+                const char* gdk_backend_wk = ::getenv("GDK_BACKEND");
+                // The EGL-less fallback above may have just forced X11.
+                const bool x11_backend_wk = gdk_backend_wk && boost::starts_with(gdk_backend_wk, "x11");
+                const char* wayland_env_dmabuf = ::getenv("WAYLAND_DISPLAY");
+                if (!x11_backend_wk && wayland_env_dmabuf && *wayland_env_dmabuf &&
+                    ::access("/proc/driver/nvidia/version", F_OK) == 0 &&
+                    WebView::WebKitAtLeast(2, 46)) {
+                    BOOST_LOG_TRIVIAL(info) << "NVIDIA proprietary driver on Wayland: disabling the WebKit DMA-BUF renderer (GNOME/gtk#8056 workaround).";
+                    ::setenv("WEBKIT_DISABLE_DMABUF_RENDERER", "1", /* replace */ false);
+                }
+            }
+            #endif
+
             // XInitThreads is needed before GStreamer may use Xlib. On
             // native Wayland without DISPLAY, GStreamer uses waylandsink
             // (no Xlib involved), so the call is skipped.

src/slic3r/GUI/Widgets/WebView.cpp

@@ -69,6 +69,10 @@ webkit_web_view_run_javascript_finish                (WebKitWebView
 						      GError                    **error);
 WEBKIT_API void
 webkit_javascript_result_unref              (WebKitJavascriptResult *js_result);
+WEBKIT_API unsigned int
+webkit_get_major_version                    (void);
+WEBKIT_API unsigned int
+webkit_get_minor_version                    (void);
 }
 #endif
 
@@ -401,6 +405,21 @@ bool WebView::NeedsRecreateOnShow()
     return false;
 #endif
 }
+
+bool WebView::WebKitAtLeast(int major, int minor)
+{
+#if defined(__linux__)
+    const unsigned int running_major = webkit_get_major_version();
+    if (running_major != static_cast<unsigned int>(major))
+        return running_major > static_cast<unsigned int>(major);
+    return webkit_get_minor_version() >= static_cast<unsigned int>(minor);
+#else
+    (void) major;
+    (void) minor;
+    return false;
+#endif
+}
+
 #if wxUSE_WEBVIEW_EDGE
 bool WebView::CheckWebViewRuntime()
 {

src/slic3r/GUI/Widgets/WebView.hpp

@@ -30,6 +30,10 @@ public:
     // ignoring every navigation. A panel that gets true here recreates its view on first Show().
     static bool NeedsRecreateOnShow();
 
+    // Runtime version of the linked WebKitGTK, for gating the Linux DMA-BUF
+    // renderer workaround. Returns false on non-GTK builds.
+    static bool WebKitAtLeast(int major, int minor);
+
     static void RecreateAll();
 };