Fix Crash Selecting a User Printer Whose Parent Preset Is Not Loaded

A user preset can inherit a system preset from a vendor that is not
installed. get_preset_base() returns null for it, and
get_selected_preset_base() dereferenced that unconditionally, so picking
the printer crashed while building the shared profiles notification URL.
Fall back to the selected preset itself. The create printer and create
filament dialogs had the same null dereference on such presets.

.claude/skills/orca-wxwidgets/references/platforms.md

@@ -574,8 +574,7 @@ DMABUF workaround and then branches on `GDK_BACKEND` (an `x11` prefix means the
 paths, when `/proc/driver/nvidia/version` exists and the linked WebKitGTK honours the switch (>= 2.44,
 `WebView::SupportsForceSharedMemory()`), it sets `WEBKIT_DMABUF_RENDERER_FORCE_SHM=1` and
 `WEBKIT_FORCE_DMABUF_RENDERER=1` (non-replacing): the proprietary driver cannot back WebKit's hardware
-DMABUF renderer. On a hypervisor guest (`/proc/cpuinfo` `hypervisor` flag) and WebKitGTK >= 2.44 it sets
-`WEBKIT_DMABUF_RENDERER_FORCE_SHM=1` alone, since virtual GPUs cannot back the hardware path either. On the default path it forces `GDK_BACKEND=x11` when wx lacks EGL and `WAYLAND_DISPLAY`
+DMABUF renderer. On the default path it forces `GDK_BACKEND=x11` when wx lacks EGL and `WAYLAND_DISPLAY`
 is set, and sets `WEBKIT_DISABLE_COMPOSITING_MODE=1` (non-replacing) inside that branch when the linked
 WebKitGTK is older than 2.42: a forced X11 backend in a Wayland session is the only default-path case
 that runs through XWayland, which `DISPLAY` and `WAYLAND_DISPLAY` alone do not tell you (a native

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

@@ -568,18 +568,13 @@ vue-resize workaround script and sets a persistent SQLite cookie store on the vi
 ## WebKitGTK on Linux sessions
 
 **Mechanism.** `CLI::run` (`src/OrcaSlicer.cpp`, under `#ifdef __WXGTK__`, before GTK initialises)
-sets the DMABUF workarounds and then branches on `GDK_BACKEND`:
+sets the NVIDIA DMABUF workaround and then branches on `GDK_BACKEND`:
 - **Both paths**, before the split: when `/proc/driver/nvidia/version` exists and the linked WebKitGTK
   honours the switch (>= 2.44, `WebView::SupportsForceSharedMemory()`), it sets
   `WEBKIT_DMABUF_RENDERER_FORCE_SHM=1` and `WEBKIT_FORCE_DMABUF_RENDERER=1` non-replacing. The
   proprietary driver cannot back WebKit's hardware DMABUF renderer, so the shared-memory transport keeps
   accelerated compositing instead of dropping it; `WEBKIT_FORCE_DMABUF_RENDERER` clears the
   Debian/Ubuntu/openSUSE `isNVIDIA()` early return, which otherwise returns before the FORCE_SHM check.
-- **Hypervisor guests**, same position: when `is_hypervisor_guest()` (the `hypervisor` flag in
-  `/proc/cpuinfo`) and WebKitGTK >= 2.44, it sets `WEBKIT_DMABUF_RENDERER_FORCE_SHM=1` non-replacing.
-  Virtual GPUs (VirtualBox VMSVGA, VMware, QEMU) cannot back the hardware DMABUF path either, and
-  FORCE_SHM alone was confirmed to fix web views in VirtualBox; the `WEBKIT_FORCE_DMABUF_RENDERER` pair
-  is not needed without the Debian `isNVIDIA()` patch. The flag is x86-only, so ARM guests are not covered.
 - **Default path** (`GDK_BACKEND` unset or not starting with `x11`): if wx lacks EGL (`!wxHAS_EGL`) and
   `WAYLAND_DISPLAY` is set, it forces `GDK_BACKEND=x11`, and in that same branch it sets
   `WEBKIT_DISABLE_COMPOSITING_MODE=1` non-replacing when the linked WebKitGTK predates 2.42
@@ -595,9 +590,9 @@ Runtime backend detection elsewhere uses Orca's `is_running_on_wayland()` / `is_
 (see `references/platforms.md`), not these environment variables.
 
 **Pitfall.**
-- **Rule:** On NVIDIA and hypervisor guests reach for `WEBKIT_DMABUF_RENDERER_FORCE_SHM` before
-  `WEBKIT_DISABLE_COMPOSITING_MODE`. **Why:** the proprietary driver and virtual GPUs cannot back WebKit's
-  hardware DMABUF renderer, leaving web views blank or slow; FORCE_SHM keeps accelerated compositing and only
+- **Rule:** On NVIDIA reach for `WEBKIT_DMABUF_RENDERER_FORCE_SHM` before
+  `WEBKIT_DISABLE_COMPOSITING_MODE`. **Why:** the proprietary driver cannot back WebKit's hardware
+  DMABUF renderer, leaving web views blank or slow; FORCE_SHM keeps accelerated compositing and only
   skips the hardware path, while disabling compositing drops it. Threaded scrolling is a separate,
   release-dependent default (off in 2.44/2.45, on from 2.46). `WEBKIT_DISABLE_DMABUF_RENDERER` is not a
   substitute — it is read first, leaves the transport set empty (no compositing from 2.44 on, where the

src/OrcaSlicer.cpp

@@ -1126,19 +1126,6 @@ static void load_downward_settings_list_from_config(std::string config_file, std
     }
 }
 
-#ifdef __WXGTK__
-// Virtual GPUs (VirtualBox, VMware, QEMU) cannot back WebKit's hardware DMABUF renderer.
-static bool is_hypervisor_guest()
-{
-    std::ifstream cpuinfo("/proc/cpuinfo");
-    std::string line;
-    while (std::getline(cpuinfo, line))
-        if (boost::starts_with(line, "flags"))
-            return line.find(" hypervisor") != std::string::npos;
-    return false;
-}
-#endif
-
 int CLI::run(int argc, char **argv)
 {
     // Mark the main thread for the debugger and for runtime checks.
@@ -1189,9 +1176,6 @@ int CLI::run(int argc, char **argv)
             ::setenv("WEBKIT_FORCE_DMABUF_RENDERER", "1", /* replace */ false);
         }
 
-        if (is_hypervisor_guest() && WebView::SupportsForceSharedMemory())
-            ::setenv("WEBKIT_DMABUF_RENDERER_FORCE_SHM", "1", /* replace */ false);
-
         if (x11_opt_in) {
             // ===== X11 / XWayland (opted in via GDK_BACKEND=x11) =====
             BOOST_LOG_TRIVIAL(info) << "GDK_BACKEND=x11 detected; applying v2.3.2 X11/XWayland workarounds.";

src/libslic3r/Preset.hpp

@@ -756,7 +756,14 @@ public:
     Preset&         get_edited_preset()         { return m_edited_preset; }
     const Preset&   get_edited_preset() const   { return m_edited_preset; }
 
-    const Preset& get_selected_preset_base() const { return *get_preset_base(m_presets[m_idx_selected]); }
+    // The root of the selected preset's inherits chain, or the selected preset itself when
+    // the chain names a preset that is not loaded (e.g. a vendor that is not installed).
+    const Preset& get_selected_preset_base() const
+    {
+        const Preset &selected = m_presets[m_idx_selected];
+        const Preset *base     = get_preset_base(selected);
+        return base ? *base : selected;
+    }
 
     // Return the last saved preset.
 //  const Preset&   get_saved_preset() const { return m_saved_preset; }

src/libvgcode/src/Layers.cpp

@@ -75,7 +75,7 @@ std::vector<float> Layers::get_zs() const
 
 size_t Layers::get_layer_id_at(float z) const
 {
-    auto iter = std::upper_bound(m_items.begin(), m_items.end(), z, [](float z, const Item& item) { return item.z > z; });
+    auto iter = std::upper_bound(m_items.begin(), m_items.end(), z, [](float z, const Item& item) { return item.z < z; });
     return std::distance(m_items.begin(), iter);
 }
 

src/slic3r/GUI/CreatePresetsDialog.cpp

@@ -3151,7 +3151,7 @@ void CreatePrinterPresetDialog::set_current_visible_printer()
     m_printer_name_to_preset.clear();
     for (const Preset &printer_preset : printer_presets) {
         if (!printer_preset.is_visible) continue;
-        if (preset_bundle->printers.get_preset_base(printer_preset)->name != printer_preset.name) continue;
+        if (preset_bundle->printers.get_preset_base(printer_preset) != &printer_preset) continue;
         if (auto printer_model = dynamic_cast<ConfigOptionString*>(const_cast<Preset&>(printer_preset).config.option("printer_model", false))) {
             if (m_printer_name_to_preset.find(printer_model->value) == m_printer_name_to_preset.end()) {
                 printer_choice.push_back(from_u8(printer_model->value));
@@ -4962,7 +4962,7 @@ void CreatePresetForPrinterDialog::get_visible_printer_and_compatible_filament_p
                     if (filament_preset.is_default || !filament_preset.is_compatible || filament_preset.is_project_embedded) continue;
                     ConfigOptionStrings *filament_types;
                     const Preset *       filament_preset_base = m_preset_bundle->filaments.get_preset_base(filament_preset);
-                    if (filament_preset_base == &filament_preset) {
+                    if (filament_preset_base == &filament_preset || filament_preset_base == nullptr) {
                         filament_types = dynamic_cast<ConfigOptionStrings *>(const_cast<Preset *>(&filament_preset)->config.option("filament_type"));
                     } else {
                         filament_types = dynamic_cast<ConfigOptionStrings *>(const_cast<Preset *>(filament_preset_base)->config.option("filament_type"));

src/slic3r/GUI/Plater.cpp

@@ -21178,12 +21178,7 @@ void Plater::print_job_finished(wxCommandEvent &evt)
     Slic3r::DeviceManager* dev = Slic3r::GUI::wxGetApp().getDeviceManager();
     if (!dev) return;
 
-    const std::string dev_id = evt.GetString().ToStdString();
-    MachineObject* selected = dev->get_selected_machine();
-    // After a LAN print, the completion event reselects the same printer.
-    // Keep the active session while asynchronous status traffic may still be in flight.
-    if (!selected || selected->get_dev_id() != dev_id || selected->connection_type() != "lan")
-        dev->set_selected_machine(dev_id);
+    dev->set_selected_machine(evt.GetString().ToStdString());
     p->main_frame->request_select_tab(TAB_ID_MONITOR);
     // Selects the status page on a built Device tab; one built by the switch starts there.
     MonitorPanel* curr_monitor = MonitorPanel::if_built();

tests/libslic3r/test_preset_bundle_loading.cpp

@@ -1219,6 +1219,24 @@ TEST_CASE("find_preset2 auto-matches removed Generic vendor profiles to the libr
     CHECK(bundle.filaments.find_preset2("BrandX Generic PETG", /*auto_match=*/true) == nullptr);
 }
 
+TEST_CASE("The selected preset is its own base when its parent is not loaded", "[Preset]")
+{
+    PresetCollection printers(Preset::TYPE_PRINTER, Preset::printer_options(),
+                              static_cast<const PrintRegionConfig &>(FullPrintConfig::defaults()));
+    add_inmemory_preset(printers, "Printer");
+    add_inmemory_preset(printers, "User Printer", "Printer");
+    add_inmemory_preset(printers, "Orphan Printer", "Uninstalled Vendor Printer");
+
+    printers.select_preset_by_name("User Printer", true);
+    REQUIRE(printers.get_selected_preset_name() == "User Printer");
+    CHECK(printers.get_selected_preset_base().name == "Printer");
+
+    printers.select_preset_by_name("Orphan Printer", true);
+    REQUIRE(printers.get_selected_preset_name() == "Orphan Printer");
+    REQUIRE(printers.get_preset_base(printers.get_selected_preset()) == nullptr);
+    CHECK(printers.get_selected_preset_base().name == "Orphan Printer");
+}
+
 TEST_CASE("Renamed parent is normalized into a loaded preset's inherits", "[Preset][Rename]")
 {
     ScopedTemporaryDir   temp_dir;