Fill Settings Missing From a CLI Project From Its System Presets

A project saved before a printer or process option existed has no value
for it. The GUI takes such keys from the project's system preset; the
CLI left them at the option default, so e.g. extruder_clearance_dist_to_rod
sliced as 40 instead of the P1S's 33.

The CLI now resolves the project's system printer and process presets by
name and copies the keys the project lacks, skipping preset bookkeeping,
print-host keys, the extruder variant layout and keys the legacy handler
drops. PresetBundle::resolve_system_preset finds the vendor through its
manifest or preset cache, so it also works in release builds, which ship
vendors as caches only.

src/OrcaSlicer.cpp

@@ -2116,9 +2116,14 @@ int CLI::run(int argc, char **argv)
 
     // One resolver for the whole run, so presets from the same vendor tree share its load.
     std::unique_ptr<PresetBundle> system_preset_resolver;
-    auto resolve_preset = [&ensure_cli_preset_bundle, &system_preset_resolver](const std::string &file, DynamicPrintConfig &config,
-                                                                               std::string &config_type, const std::string &config_from,
-                                                                               bool probe_type, std::string &error) {
+    auto ensure_system_preset_resolver = [&system_preset_resolver]() -> PresetBundle & {
+        if (!system_preset_resolver)
+            system_preset_resolver = std::make_unique<PresetBundle>();
+        return *system_preset_resolver;
+    };
+    auto resolve_preset = [&ensure_cli_preset_bundle, &ensure_system_preset_resolver](const std::string &file, DynamicPrintConfig &config,
+                                                                                      std::string &config_type, const std::string &config_from,
+                                                                                      bool probe_type, std::string &error) {
         const auto *inherits = config.option<ConfigOptionString>(BBL_JSON_KEY_INHERITS);
         if (!probe_type && (inherits == nullptr || inherits->value.empty()))
             return true;
@@ -2126,9 +2131,7 @@ int CLI::run(int argc, char **argv)
         PresetBundle                 *bundle = nullptr;
         bool                          allow_source_manifest = false;
         if (config_from == "system") {
-            if (!system_preset_resolver)
-                system_preset_resolver = std::make_unique<PresetBundle>();
-            bundle                = system_preset_resolver.get();
+            bundle                = &ensure_system_preset_resolver();
             allow_source_manifest = true;
         } else {
             bundle = ensure_cli_preset_bundle(error);
@@ -3120,6 +3123,49 @@ int CLI::run(int argc, char **argv)
         return 0;
     };
 
+    // A project saved before a printer or process option existed has no value for it. The GUI takes such
+    // keys from the project's system preset (load_external_preset refreshes every key the project did not
+    // override), so fill them from there too instead of leaving them to the option default.
+    // The extruder variant keys describe the project's variant layout and are kept as they are, so an
+    // older project is not left with a variant list from one layout and ids from another.
+    auto fill_missing_project_keys = [this, &ensure_system_preset_resolver](const std::string &system_name, Preset::Type type) {
+        if (system_name.empty())
+            return;
+        static const std::set<std::string> skip_keys = {
+            "inherits", "compatible_printers", "compatible_prints", "compatible_printers_condition", "compatible_prints_condition",
+            "print_settings_id", "filament_settings_id", "printer_settings_id",
+            "print_host", "print_host_webui", "printhost_apikey", "printhost_cafile", "printhost_user", "printhost_password", "printhost_port",
+            "printer_extruder_id", "printer_extruder_variant", "print_extruder_id", "print_extruder_variant", "extruder_variant_list"};
+        const std::vector<std::string> &options = type == Preset::TYPE_PRINTER ? Preset::printer_options() : Preset::print_options();
+        // Keys the legacy handler drops on load can never be in a project, so they do not count as missing.
+        auto dropped_on_load = [](std::string key) {
+            std::string value;
+            PrintConfigDef::handle_legacy(key, value);
+            return key.empty();
+        };
+        std::vector<std::string> missing;
+        for (const std::string &key : options)
+            if (m_print_config.option(key) == nullptr && skip_keys.count(key) == 0 && !dropped_on_load(key))
+                missing.push_back(key);
+        if (missing.empty())
+            return;
+        DynamicPrintConfig system_config;
+        std::string        error;
+        if (!ensure_system_preset_resolver().resolve_system_preset(system_config, type, system_name, config_substitution_rule, error)) {
+            BOOST_LOG_TRIVIAL(warning) << boost::format("CLI: system preset '%1%' not resolved (%2%); keys missing from the project keep their defaults") % system_name % error;
+            return;
+        }
+        for (const std::string &key : missing)
+            if (const ConfigOption *opt = system_config.option(key)) {
+                m_print_config.set_key_value(key, opt->clone());
+                BOOST_LOG_TRIVIAL(info) << boost::format("CLI: %1% missing from the project, taken from '%2%': %3%") % key % system_name % opt->serialize();
+            }
+    };
+    if (new_printer_name.empty())
+        fill_missing_project_keys(current_printer_system_name, Preset::TYPE_PRINTER);
+    if (new_process_name.empty())
+        fill_missing_project_keys(current_process_system_name, Preset::TYPE_PRINT);
+
     std::vector<std::string>& different_settings = m_print_config.option<ConfigOptionStrings>("different_settings_to_system", true)->values;
     std::vector<std::string>& inherits_group = m_print_config.option<ConfigOptionStrings>("inherits_group", true)->values;
     inherits_group.resize(filament_count + 2, std::string());

src/libslic3r/Format/3mf.cpp

@@ -307,17 +307,14 @@ bool PrusaFileParser::check_3mf_from_prusa(const std::string filename)
 
             mz_zip_archive_file_stat stat;
             if (!mz_zip_reader_file_stat(&archive, model_file_index, &stat)) goto EXIT;
-            // expat sizes its buffer with an int, so a larger entry cannot be parsed in one piece.
-            if (stat.m_uncomp_size > static_cast<mz_uint64>(std::numeric_limits<int>::max())) goto EXIT;
 
-            const int xml_size = static_cast<int>(stat.m_uncomp_size);
-            void *parser_buffer = XML_GetBuffer(m_parser, xml_size);
+            void *parser_buffer = XML_GetBuffer(m_parser, (int) stat.m_uncomp_size);
             if (parser_buffer == nullptr) goto EXIT;
 
-            mz_bool res = mz_zip_reader_extract_file_to_mem(&archive, stat.m_filename, parser_buffer, static_cast<size_t>(xml_size), 0);
+            mz_bool res = mz_zip_reader_extract_file_to_mem(&archive, stat.m_filename, parser_buffer, (size_t) stat.m_uncomp_size, 0);
             if (res == 0) goto EXIT;
 
-            XML_ParseBuffer(m_parser, xml_size, 1);
+            XML_ParseBuffer(m_parser, (int) stat.m_uncomp_size, 1);
         }
     }
 
@@ -1349,26 +1346,19 @@ ModelVolumeType type_from_string(const std::string &s)
         XML_SetUserData(m_xml_parser, (void*)this);
         XML_SetElementHandler(m_xml_parser, _3MF_Importer::_handle_start_config_xml_element, _3MF_Importer::_handle_end_config_xml_element);
 
-        // expat sizes its buffer with an int, so a larger entry cannot be parsed in one piece.
-        if (stat.m_uncomp_size > static_cast<mz_uint64>(std::numeric_limits<int>::max())) {
-            add_error("Found invalid size");
-            return false;
-        }
-        const int xml_size = static_cast<int>(stat.m_uncomp_size);
-
-        void* parser_buffer = XML_GetBuffer(m_xml_parser, xml_size);
+        void* parser_buffer = XML_GetBuffer(m_xml_parser, (int)stat.m_uncomp_size);
         if (parser_buffer == nullptr) {
             add_error("Unable to create buffer");
             return false;
         }
 
-        mz_bool res = mz_zip_reader_extract_file_to_mem(&archive, stat.m_filename, parser_buffer, static_cast<size_t>(xml_size), 0);
+        mz_bool res = mz_zip_reader_extract_file_to_mem(&archive, stat.m_filename, parser_buffer, (size_t)stat.m_uncomp_size, 0);
         if (res == 0) {
             add_error("Error while reading config data to buffer");
             return false;
         }
 
-        if (!XML_ParseBuffer(m_xml_parser, xml_size, 1)) {
+        if (!XML_ParseBuffer(m_xml_parser, (int)stat.m_uncomp_size, 1)) {
             char error_buf[1024];
             ::sprintf(error_buf, "Error (%s) while parsing xml file at line %d", XML_ErrorString(XML_GetErrorCode(m_xml_parser)), (int)XML_GetCurrentLineNumber(m_xml_parser));
             add_error(error_buf);

src/libslic3r/Format/bbs_3mf.cpp

@@ -2508,26 +2508,19 @@ void PlateData::parse_filament_info(GCodeProcessorResult *result)
         XML_SetEntityDeclHandler(m_xml_parser, nullptr);
         XML_SetExternalEntityRefHandler(m_xml_parser, nullptr);
 
-        // expat sizes its buffer with an int, so a larger entry cannot be parsed in one piece.
-        if (stat.m_uncomp_size > static_cast<mz_uint64>(std::numeric_limits<int>::max())) {
-            add_error("Found invalid size");
-            return false;
-        }
-        const int xml_size = static_cast<int>(stat.m_uncomp_size);
-
-        void* parser_buffer = XML_GetBuffer(m_xml_parser, xml_size);
+        void* parser_buffer = XML_GetBuffer(m_xml_parser, (int)stat.m_uncomp_size);
         if (parser_buffer == nullptr) {
             add_error("Unable to create buffer");
             return false;
         }
 
-        mz_bool res = mz_zip_reader_extract_file_to_mem(&archive, stat.m_filename, parser_buffer, static_cast<size_t>(xml_size), 0);
+        mz_bool res = mz_zip_reader_extract_file_to_mem(&archive, stat.m_filename, parser_buffer, (size_t)stat.m_uncomp_size, 0);
         if (res == 0) {
             add_error("Error while reading config data to buffer");
             return false;
         }
 
-        if (!XML_ParseBuffer(m_xml_parser, xml_size, 1)) {
+        if (!XML_ParseBuffer(m_xml_parser, (int)stat.m_uncomp_size, 1)) {
             char error_buf[1024];
             ::snprintf(error_buf, 1024, "Error (%s) while parsing xml file at line %d", XML_ErrorString(XML_GetErrorCode(m_xml_parser)), (int)XML_GetCurrentLineNumber(m_xml_parser));
             add_error(error_buf);

src/libslic3r/GCode.cpp

@@ -2504,7 +2504,8 @@ void GCode::do_export(Print* print, const char* path, GCodeProcessorResult* resu
 
     {
         LifecycleEventContext ctx;
-        ctx.name = std::to_string(print->model().id().id);
+        ctx.id = std::to_string(print->model().id().id);
+        ctx.name = print->get_model_name();
         ctx.code = LifecycleEvtCode::Ok;
         ctx.msg  = path;
         ctx.cancellation_check = [print]() { return print->canceled(); };
@@ -2556,7 +2557,8 @@ void GCode::do_export(Print* print, const char* path, GCodeProcessorResult* resu
         }
         {
             LifecycleEventContext ctx;
-            ctx.name = std::to_string(print->model().id().id);
+            ctx.id = std::to_string(print->model().id().id);
+            ctx.name = print->get_model_name();
             ctx.code = LifecycleEvtCode::Error;
             ctx.msg  = std::string(path) + "\n" + err_msg;
             ctx.cancellation_check = [print]() { return print->canceled(); };
@@ -2580,7 +2582,8 @@ void GCode::do_export(Print* print, const char* path, GCodeProcessorResult* resu
         boost::nowide::remove(path_tmp.c_str());
         {
             LifecycleEventContext ctx;
-            ctx.name = std::to_string(print->model().id().id);
+            ctx.id = std::to_string(print->model().id().id);
+            ctx.name = print->get_model_name();
             ctx.code = LifecycleEvtCode::Error;
             ctx.msg  = std::string(path) + "\n" + ex.what();
             ctx.cancellation_check = [print]() { return print->canceled(); };
@@ -2693,7 +2696,8 @@ void GCode::do_export(Print* print, const char* path, GCodeProcessorResult* resu
     if (ret) {
         {
             LifecycleEventContext ctx;
-            ctx.name = std::to_string(print->model().id().id);
+            ctx.id = std::to_string(print->model().id().id);
+            ctx.name = print->get_model_name();
             ctx.code = LifecycleEvtCode::Error;
             ctx.msg  = std::string(path) + "\nFailed to rename the output G-code file: " + ret.message();
             ctx.cancellation_check = [print]() { return print->canceled(); };
@@ -2712,7 +2716,8 @@ void GCode::do_export(Print* print, const char* path, GCodeProcessorResult* resu
 
     {
         LifecycleEventContext ctx;
-        ctx.name = std::to_string(print->model().id().id);
+        ctx.id = std::to_string(print->model().id().id);
+        ctx.name = print->get_model_name();
         ctx.code = LifecycleEvtCode::Ok;
         ctx.msg  = path;
         ctx.cancellation_check = [print]() { return print->canceled(); };

src/libslic3r/PresetBundle.cpp

@@ -575,18 +575,20 @@ bool PresetBundle::resolve_preset_config(DynamicPrintConfig &config, Preset::Typ
 const PresetBundle *PresetBundle::load_source_vendor(const boost::filesystem::path &root_dir,
                                                     const std::string &vendor_id,
                                                     ForwardCompatibilitySubstitutionRule compatibility_rule,
-                                                    std::string &error)
+                                                    std::string &error, bool allow_cache)
 {
-    auto key = std::make_tuple(root_dir.string(), vendor_id, compatibility_rule);
+    auto key = std::make_tuple(root_dir.string(), vendor_id, compatibility_rule, allow_cache);
     if (auto it = m_source_vendor_bundles.find(key); it != m_source_vendor_bundles.end())
         return it->second.get();
 
     // The library loads with no base of its own, so the tree a vendor inherits from
     // is the same one that resolves the library's own presets.
-    const PresetBundle *library = nullptr;
+    const std::string   library_file = std::string(ORCA_FILAMENT_LIBRARY);
+    const PresetBundle *library      = nullptr;
     if (vendor_id != ORCA_FILAMENT_LIBRARY &&
-        boost::filesystem::is_regular_file(root_dir / (std::string(ORCA_FILAMENT_LIBRARY) + ".json"))) {
-        library = load_source_vendor(root_dir, ORCA_FILAMENT_LIBRARY, compatibility_rule, error);
+        (boost::filesystem::is_regular_file(root_dir / (library_file + ".json")) ||
+         (allow_cache && boost::filesystem::is_regular_file(root_dir / (library_file + ".opc"))))) {
+        library = load_source_vendor(root_dir, ORCA_FILAMENT_LIBRARY, compatibility_rule, error, allow_cache);
         if (library == nullptr) {
             error = "OrcaFilamentLibrary contains invalid presets";
             return nullptr;
@@ -595,7 +597,7 @@ const PresetBundle *PresetBundle::load_source_vendor(const boost::filesystem::pa
 
     auto bundle = std::make_unique<PresetBundle>();
     bundle->m_preserve_vendor_source_paths = true;
-    bundle->load_vendor_configs_from_json(root_dir.string(), vendor_id, LoadSystem, compatibility_rule, library, false);
+    bundle->load_vendor_configs_from_json(root_dir.string(), vendor_id, LoadSystem, compatibility_rule, library, allow_cache);
     if (bundle->error_count() != 0) {
         error = "Vendor bundle contains invalid presets";
         return nullptr;
@@ -638,6 +640,43 @@ bool PresetBundle::resolve_preset_config_type(DynamicPrintConfig &config, Preset
     return true;
 }
 
+bool PresetBundle::resolve_system_preset(DynamicPrintConfig &config, Preset::Type type, const std::string &name,
+                                         ForwardCompatibilitySubstitutionRule compatibility_rule, std::string &error)
+{
+    const std::string vendor_id = find_preset_vendor(name, type);
+    if (vendor_id.empty()) {
+        error = "No vendor lists the preset";
+        return false;
+    }
+    // Release builds ship a vendor as its preset cache alone, without the profile JSONs.
+    auto installed = [&vendor_id](const fs::path &root) {
+        return fs::is_regular_file(root / (vendor_id + ".json")) || fs::is_regular_file(root / (vendor_id + ".opc"));
+    };
+    fs::path root_dir = fs::path(data_dir()) / PRESET_SYSTEM_DIR;
+    if (!installed(root_dir))
+        root_dir = fs::path(resources_dir()) / PRESET_PROFILES_DIR;
+    const bool cache_only = !fs::is_regular_file(root_dir / (vendor_id + ".json"));
+
+    try {
+        const PresetBundle *vendor = load_source_vendor(root_dir, vendor_id, compatibility_rule, error, cache_only);
+        if (vendor == nullptr)
+            return false;
+        const PresetCollection &collection = type == Preset::TYPE_PRINTER ? vendor->printers :
+                                             type == Preset::TYPE_PRINT   ? vendor->prints : vendor->filaments;
+        const Preset *preset = collection.find_preset(name, false);
+        if (preset == nullptr) {
+            error = "Preset was not found in its vendor bundle";
+            return false;
+        }
+        config = preset->config;
+    } catch (const std::exception &ex) {
+        error = ex.what();
+        return false;
+    }
+    error.clear();
+    return true;
+}
+
 PresetBundle::PresetBundle(const PresetBundle &rhs)
 {
     *this = rhs;

src/libslic3r/PresetBundle.hpp

@@ -273,6 +273,10 @@ public:
                                     const std::string &source_file,
                                     ForwardCompatibilitySubstitutionRule compatibility_rule,
                                     std::string &error, bool allow_source_manifest = true);
+    // Resolve a system preset by name. The vendor tree is read from data_dir()/system when installed
+    // there, as the GUI reads it, and from the bundled profiles otherwise.
+    bool resolve_system_preset(DynamicPrintConfig &config, Preset::Type type, const std::string &name,
+                               ForwardCompatibilitySubstitutionRule compatibility_rule, std::string &error);
 
     // Load selections (current print, current filaments, current printer) from config.ini
     // This is done just once on application start up.
@@ -663,13 +667,14 @@ private:
     // Vendor trees loaded by resolve_preset_config's manifest path, so every preset
     // resolved through this bundle shares one load per source root and vendor. The
     // filament library is one such tree, shared by every vendor under its root.
-    std::map<std::tuple<std::string, std::string, ForwardCompatibilitySubstitutionRule>, std::unique_ptr<PresetBundle>>
+    // A tree read from its preset cache is kept apart: its presets carry no source file.
+    std::map<std::tuple<std::string, std::string, ForwardCompatibilitySubstitutionRule, bool>, std::unique_ptr<PresetBundle>>
         m_source_vendor_bundles;
 
     const PresetBundle *load_source_vendor(const boost::filesystem::path &root_dir,
                                            const std::string &vendor_id,
                                            ForwardCompatibilitySubstitutionRule compatibility_rule,
-                                           std::string &error);
+                                           std::string &error, bool allow_cache = false);
 
     // Orca: validation only - flag any printer with two or more compatible
     // filament presets sharing one filament_id (ambiguous AMS subtype match).

src/libslic3r/Print.cpp

@@ -2717,7 +2717,8 @@ void Print::process(long long *time_cost_with_cache, bool use_cache)
 
     {
         LifecycleEventContext ctx;
-        ctx.name = std::to_string(m_model.id().id);
+        ctx.id = std::to_string(m_model.id().id);
+        ctx.name = get_model_name();
         ctx.code = LifecycleEvtCode::Ok;
         ctx.cancellation_check = [this]() { return canceled(); };
         fire_lifecycle_event(LifecycleEvent::SliceStarted, ctx);
@@ -3344,7 +3345,8 @@ void Print::process(long long *time_cost_with_cache, bool use_cache)
 
     {
         LifecycleEventContext ctx;
-        ctx.name = std::to_string(m_model.id().id);
+        ctx.id = std::to_string(m_model.id().id);
+        ctx.name = get_model_name();
         ctx.code = LifecycleEvtCode::Ok;
         ctx.cancellation_check = [this]() { return canceled(); };
         fire_lifecycle_event(LifecycleEvent::SliceGeometryFinished, ctx);
@@ -4950,7 +4952,8 @@ void Print::export_gcode_from_previous_file(const std::string& file, GCodeProces
 {
     {
         LifecycleEventContext ctx;
-        ctx.name = std::to_string(m_model.id().id);
+        ctx.id = std::to_string(m_model.id().id);
+        ctx.name = get_model_name();
         ctx.code = LifecycleEvtCode::Ok;
         ctx.msg  = file;
         ctx.cancellation_check = [this]() { return canceled(); };
@@ -4980,7 +4983,8 @@ void Print::export_gcode_from_previous_file(const std::string& file, GCodeProces
         BOOST_LOG_TRIVIAL(error) << __FUNCTION__ <<  boost::format(": found errors when process gcode file %1%") %file.c_str();
         {
             LifecycleEventContext ctx;
-            ctx.name = std::to_string(m_model.id().id);
+            ctx.id = std::to_string(m_model.id().id);
+            ctx.name = get_model_name();
             ctx.code = LifecycleEvtCode::Error;
             ctx.msg  = file + "\n" + ex.what();
             ctx.cancellation_check = [this]() { return canceled(); };
@@ -4994,7 +4998,8 @@ void Print::export_gcode_from_previous_file(const std::string& file, GCodeProces
 
     {
         LifecycleEventContext ctx;
-        ctx.name = std::to_string(m_model.id().id);
+        ctx.id = std::to_string(m_model.id().id);
+        ctx.name = get_model_name();
         ctx.code = LifecycleEvtCode::Ok;
         ctx.msg  = file;
         ctx.cancellation_check = [this]() { return canceled(); };

src/libvgcode/src/Shaders.hpp

@@ -34,6 +34,10 @@ static const char* Segments_Vertex_Shader =
 // ORCA: 0 during the shadow caster pass - the bias below shifts eye_position but not
 // world_position, so the caster would write a depth the receiver never looks up.
 "uniform float bias_scale;\n"
+// draw the instances last to first, top layers before the ones they hide, so that early depth
+// rejection discards most of the hidden fragments; set when the camera looks down on the print
+"uniform int reverse_order;\n"
+"uniform int instance_count;\n"
 "in int vertex_id;\n"
 "out vec3 color;\n"
 "// ORCA: realistic view - the light the shadow map is able to block, kept apart from the\n"
@@ -59,7 +63,8 @@ static const char* Segments_Vertex_Shader =
 "  return top_diffuse + front_diffuse + top_specular;\n"
 "}\n"
 "void main() {\n"
-"  int id_a = int(texelFetch(segment_index_tex, gl_InstanceID).r);\n"
+"  int instance = (reverse_order != 0) ? instance_count - 1 - gl_InstanceID : gl_InstanceID;\n"
+"  int id_a = int(texelFetch(segment_index_tex, instance).r);\n"
 "  int id_b = id_a + 1;\n"
 "  vec3 pos_a = texelFetch(position_tex, id_a).xyz;\n"
 "  vec3 pos_b = texelFetch(position_tex, id_b).xyz;\n"

src/libvgcode/src/ViewerImpl.cpp

@@ -763,6 +763,8 @@ void ViewerImpl::init(const std::string& opengl_context_version)
     m_uni_segments_height_width_angle_tex_id = glGetUniformLocation(m_segments_shader_id, "height_width_angle_tex");
     m_uni_segments_colors_tex_id             = glGetUniformLocation(m_segments_shader_id, "color_tex");
     m_uni_segments_segment_index_tex_id      = glGetUniformLocation(m_segments_shader_id, "segment_index_tex");
+    m_uni_segments_reverse_order_id          = glGetUniformLocation(m_segments_shader_id, "reverse_order");
+    m_uni_segments_instance_count_id         = glGetUniformLocation(m_segments_shader_id, "instance_count");
     // ORCA: realistic view
     m_uni_segments_shadow_map_id             = glGetUniformLocation(m_segments_shader_id, "shadow_map");
     m_uni_segments_shadow_light_vp_id        = glGetUniformLocation(m_segments_shader_id, "shadow_light_vp");
@@ -2090,6 +2092,15 @@ void ViewerImpl::render_segments(const Mat4x4& view_matrix, const Mat4x4& projec
     glsafe(glUniformMatrix4fv(m_uni_segments_view_matrix_id, 1, GL_FALSE, view_matrix.data()));
     glsafe(glUniformMatrix4fv(m_uni_segments_projection_matrix_id, 1, GL_FALSE, projection_matrix.data()));
     glsafe(glUniform3fv(m_uni_segments_camera_position_id, 1, camera_position.data()));
+    // The segments come in print order, bottom layer first. Seen from above, that is back to front,
+    // and every hidden fragment is shaded before the one that covers it. Drawing them last to first
+    // lets the depth test reject the hidden ones instead. The camera looks down when the world's
+    // up axis points towards it, which is the view matrix's (2, 2) entry being positive.
+    const bool top_down = !m_rendering_shadow_casters && view_matrix[10] > 0.0f;
+    glsafe(glUniform1i(m_uni_segments_reverse_order_id, top_down ? 1 : 0));
+#ifndef ENABLE_OPENGL_ES
+    glsafe(glUniform1i(m_uni_segments_instance_count_id, static_cast<int>(m_enabled_segments_count)));
+#endif // ENABLE_OPENGL_ES
     // ORCA: realistic view. The depth pass writes the map it would otherwise read, so it shades
     // with the lookup off.
     glsafe(glUniform1i(m_uni_segments_shadow_map_id, m_shadow_map_texture_unit));

src/libvgcode/src/ViewerImpl.hpp

@@ -362,6 +362,8 @@ private:
     int m_uni_segments_height_width_angle_tex_id{ -1 };
     int m_uni_segments_colors_tex_id{ -1 };
     int m_uni_segments_segment_index_tex_id{ -1 };
+    int m_uni_segments_reverse_order_id{ -1 };
+    int m_uni_segments_instance_count_id{ -1 };
     int m_uni_segments_shadow_map_id{ -1 };
     int m_uni_segments_shadow_light_vp_id{ -1 };
     int m_uni_segments_shadow_intensity_id{ -1 };

src/slic3r/GUI/Plater.cpp

@@ -12800,8 +12800,6 @@ void Plater::priv::on_process_completed(SlicingProcessCompletedEvent &evt)
     notification_manager->set_slicing_progress_export_possible();
 
     // Reset the "export G-code path" name, so that the automatic background processing will be enabled again.
-    const std::string lifecycle_job_name = this->background_process.fff_print() ?
-        this->background_process.fff_print()->output_filename() : std::string();
     this->background_process.reset_export();
     // This bool stops showing export finished notification even when process_completed_with_error is false
     bool has_error = false;
@@ -12848,8 +12846,18 @@ void Plater::priv::on_process_completed(SlicingProcessCompletedEvent &evt)
 
     {
         Slic3r::LifecycleEventContext ctx;
-        ctx.name = lifecycle_job_name;
-        ctx.code = evt.cancelled() ? Slic3r::LifecycleEvtCode::Warn : (has_error ? Slic3r::LifecycleEvtCode::Error : Slic3r::LifecycleEvtCode::Ok);
+        if (const PrintBase* print = this->background_process.current_print()) {
+            const Model& model = print->model();
+            ctx.id             = std::to_string(model.id().id);
+            if (model.model_info)
+                ctx.name = model.model_info->model_name;
+        } else {
+            // Realistically Printbase* print will never be null because select_technology already asserts an active print
+            // and the worker thread asserts it before processing.
+            BOOST_LOG_TRIVIAL(warning) << __FUNCTION__ << ": slicing completed without an active print; lifecycle event has no model ID";
+        }
+        ctx.code = evt.cancelled() ? Slic3r::LifecycleEvtCode::Warn :
+                                     (has_error ? Slic3r::LifecycleEvtCode::Error : Slic3r::LifecycleEvtCode::Ok);
         ctx.msg  = evt.cancelled() ? "cancelled" : (has_error ? lifecycle_error_msg : std::string());
         Slic3r::fire_lifecycle_event(Slic3r::LifecycleEvent::SlicingJobComplete, ctx);
     }

src/slic3r/Utils/PrintHost.cpp

@@ -6,6 +6,7 @@
 #include <boost/optional.hpp>
 #include <boost/log/trivial.hpp>
 #include <boost/filesystem.hpp>
+#include <nlohmann/json.hpp>
 
 #include <wx/string.h>
 #include <wx/app.h>
@@ -115,10 +116,67 @@ std::string PrintHost::get_print_host_webui(DynamicPrintConfig* config)
     return webui_url;
 }
 
+namespace {
+
+// Moonraker (Klipper's API server) reports a raised exception as { "error": { "code", "message", "traceback" } }
+// under every host type that connects to it, often with the cause only in the traceback. Returns the reason to show,
+// or empty for any other body.
+std::string moonraker_error_reason(const std::string &body)
+{
+    const auto root = nlohmann::json::parse(body, nullptr, false);
+    const auto err  = root.find("error");
+    if (err == root.end())
+        return {};
+    const auto message   = err->find("message");
+    const auto traceback = err->find("traceback");
+    if (message == err->end() || traceback == err->end() || !message->is_string() || !traceback->is_string())
+        return {};
+
+    const auto &msg = message->get_ref<const std::string &>();
+    const auto &tb  = traceback->get_ref<const std::string &>();
+    if (msg.empty())
+        return {};
+    const auto end = tb.find_last_not_of(" \t\r\n");
+    if (end == std::string::npos)
+        return msg;
+
+    // Chained exceptions each start a new traceback; the one that failed the request is the last.
+    const auto header = tb.rfind("Traceback (most recent call last):", end);
+
+    // Tornado renders a raised HTTPError as "HTTP <code>: <reason>[ (<detail>)]", and the detail may span lines.
+    const auto code = err->find("code");
+    if (code != err->end() && code->is_number_integer()) {
+        const std::string marker = "HTTP " + std::to_string(code->get<int>()) + ": ";
+        const auto        pos    = tb.rfind(marker, end);
+        if (pos != std::string::npos && (header == std::string::npos || pos > header) && pos + marker.size() <= end) {
+            const std::string reason = tb.substr(pos + marker.size(), end + 1 - pos - marker.size());
+            // An HTTPError whose detail equals its reason, like HTTPError(401, "Unauthorized"), renders the phrase twice.
+            return reason == msg + " (" + msg + ")" ? msg : reason;
+        }
+    }
+
+    // Any other exception's type and message are everything from the first unindented line after its frames.
+    auto begin = (header == std::string::npos) ? std::string::npos : tb.find('\n', header);
+    while (begin != std::string::npos && begin < end) {
+        ++begin;
+        if (tb[begin] != ' ' && tb[begin] != '\r' && tb[begin] != '\n')
+            break;
+        begin = tb.find('\n', begin);
+    }
+    if (begin == std::string::npos || begin > end) {
+        const auto nl = tb.rfind('\n', end);
+        begin         = (nl == std::string::npos) ? 0 : nl + 1;
+    }
+    return msg + " (" + tb.substr(begin, end + 1 - begin) + ")";
+}
+
+} // namespace
+
 wxString PrintHost::format_error(const std::string &body, const std::string &error, unsigned status) const
 {
     if (status != 0) {
-        auto wxbody = wxString::FromUTF8(body.data());
+        const std::string reason = moonraker_error_reason(body);
+        auto wxbody = wxString::FromUTF8(reason.empty() ? body : reason);
         return wxString::Format("HTTP %u: %s", status, wxbody);
     } else {
         if (error.find("curl:Timeout was reached") != std::string::npos) {

tests/cli/CMakeLists.txt

@@ -15,3 +15,11 @@ set_tests_properties(cli_strict_mode PROPERTIES
     LABELS "CLI;RequiresApp"
     SKIP_RETURN_CODE 77
     TIMEOUT 900)
+
+add_test(NAME cli_project_missing_keys
+    COMMAND bash ${CMAKE_CURRENT_SOURCE_DIR}/test_cli_project_missing_keys.sh $<TARGET_FILE:OrcaSlicer> ${ORCA_CLI_TEST_PYTHON}
+        ${CMAKE_SOURCE_DIR}/resources/profiles/BBL)
+set_tests_properties(cli_project_missing_keys PROPERTIES
+    LABELS "CLI;RequiresApp"
+    SKIP_RETURN_CODE 77
+    TIMEOUT 900)

tests/cli/test_cli_project_missing_keys.sh

@@ -0,0 +1,89 @@
+#!/usr/bin/env bash
+# End-to-end check that the CLI fills settings missing from a project from the project's system presets.
+#
+# A project saved before an option existed has no value for it. The GUI takes such keys from the
+# project's system printer and process presets, not from the option defaults, and the CLI must slice
+# the project with the same values. A project is exported from the shipped Bambu Lab P1S presets, one
+# printer key and one process key are removed from it, one kept key is changed, and it is sliced again.
+#
+# usage: test_cli_project_missing_keys.sh <orca-slicer binary> <python3> <resources/profiles/BBL>
+set -u
+
+BIN="${1:-}"
+PY="${2:-python3}"
+PROFILES="${3:-}"
+# 77 is the test's SKIP_RETURN_CODE.
+[ -x "$BIN" ] || { echo "SKIP: orca-slicer binary not found: $BIN"; exit 77; }
+[ -d "$PROFILES" ] || { echo "FAIL: profiles directory not found: $PROFILES"; exit 1; }
+
+WORK="$(mktemp -d "${TMPDIR:-/tmp}/orca-cli-missing-keys.XXXXXX")"
+trap 'rm -rf "$WORK"' EXIT
+
+"$PY" - "$WORK/cube.stl" <<'EOF'
+import sys
+
+v = [(x, y, z) for z in (0, 10) for y in (0, 10) for x in (0, 10)]
+with open(sys.argv[1], "w") as f:
+    f.write("solid cube\n")
+    for a, b, c, d in ((0, 2, 3, 1), (4, 5, 7, 6), (0, 1, 5, 4), (2, 6, 7, 3), (0, 4, 6, 2), (1, 3, 7, 5)):
+        for tri in ((v[a], v[b], v[c]), (v[a], v[c], v[d])):
+            f.write("facet normal 0 0 0\nouter loop\n")
+            for p in tri:
+                f.write("vertex %g %g %g\n" % p)
+            f.write("endloop\nendfacet\n")
+    f.write("endsolid cube\n")
+EOF
+
+# slice <tag> <input> [option...]: slice into $WORK/<tag>/out.3mf with a fresh data directory.
+slice() {
+    local out="$WORK/$1" input="$2"; shift 2
+    mkdir -p "$out"
+    timeout 300 "$BIN" --datadir "$out/datadir" "$@" --slice 0 --outputdir "$out" --export-3mf out.3mf "$input" \
+        > "$out/log" 2>&1 || { echo "FAIL: $1: orca-slicer exited $?"; tail -n 40 "$out/log"; exit 1; }
+}
+
+slice base "$WORK/cube.stl" \
+    --load-settings "$PROFILES/machine/Bambu Lab P1S 0.4 nozzle.json;$PROFILES/process/0.20mm Standard @BBL X1C.json" \
+    --load-filaments "$PROFILES/filament/Bambu PLA Basic @BBL P1S 0.4 nozzle.json"
+
+# The removed keys, with their option defaults from PrintConfig.cpp, and a kept key with a new value.
+"$PY" - "$WORK/base/out.3mf" "$WORK/old.3mf" <<'EOF' || exit $?
+import json, sys, zipfile
+
+src, dst = sys.argv[1], sys.argv[2]
+missing = {"extruder_clearance_dist_to_rod": "40", "sparse_infill_density": "20%"}
+with zipfile.ZipFile(src) as zin, zipfile.ZipFile(dst, "w", zipfile.ZIP_DEFLATED) as zout:
+    for item in zin.infolist():
+        data = zin.read(item.filename)
+        if item.filename == "Metadata/project_settings.config":
+            config = json.loads(data)
+            for key, default in missing.items():
+                if config[key] == default:
+                    print("SKIP: %s is %s in the system preset, the option default, so the test cannot tell them apart" % (key, default))
+                    sys.exit(77)
+            expected = {key: config.pop(key) for key in missing}
+            expected["wall_loops"] = str(int(config["wall_loops"]) + 1)
+            config["wall_loops"] = expected["wall_loops"]
+            data = json.dumps(config, indent=4)
+        zout.writestr(item, data)
+with open(dst + ".expected.json", "w") as f:
+    json.dump(expected, f)
+EOF
+
+slice project "$WORK/old.3mf"
+
+"$PY" - "$WORK/project/out.3mf" "$WORK/old.3mf.expected.json" <<'EOF'
+import json, sys, zipfile
+
+with zipfile.ZipFile(sys.argv[1]) as z:
+    config = json.loads(z.read("Metadata/project_settings.config"))
+with open(sys.argv[2]) as f:
+    expected = json.load(f)
+errors = ["%s is %r, want %r" % (key, config.get(key), want) for key, want in expected.items() if config.get(key) != want]
+for e in errors:
+    print("FAIL: " + e)
+sys.exit(1 if errors else 0)
+EOF
+status=$?
+[ "$status" -eq 0 ] || { tail -n 40 "$WORK/project/log"; exit 1; }
+echo "PASS"

tests/fff_print/test_print.cpp

@@ -15,6 +15,9 @@
 #include "libslic3r/Layer.hpp"
 #include "libslic3r/Model.hpp"
 #include "libslic3r/GCodeReader.hpp"
+#include "libslic3r/GCode/GCodeProcessor.hpp"
+#include "libslic3r/Exception.hpp"
+#include "libslic3r/LifecycleEvents.hpp"
 
 #include "test_helpers.hpp"
 #include "test_utils.hpp"
@@ -22,7 +25,10 @@
 #include <algorithm>
 #include <fstream>
 #include <iterator>
+#include <memory>
 #include <string_view>
+#include <utility>
+#include <vector>
 
 using namespace Slic3r;
 using namespace Slic3r::Test;
@@ -224,8 +230,88 @@ std::string resolved_output_name(Model& model, const std::string& format, const
     return print.output_filename(filename_base);
 }
 
+struct ScopedLifecycleHook
+{
+    explicit ScopedLifecycleHook(LifecycleHookFn hook) { set_lifecycle_hook_fn(std::move(hook)); }
+    ~ScopedLifecycleHook() { set_lifecycle_hook_fn(nullptr); }
+};
+
 } // namespace
 
+TEST_CASE("Slicing lifecycle events identify the model", "[Print][LifecycleEvents]")
+{
+    struct ObservedEvent {
+        LifecycleEvent event;
+        std::string id;
+        std::string name;
+    };
+    std::vector<ObservedEvent> events;
+    ScopedLifecycleHook hook([&](LifecycleEvent event, const LifecycleEventContext& ctx) {
+        events.push_back({ event, ctx.id, ctx.name });
+    });
+
+    Print print;
+    Model model;
+    ModelInfo info;
+    info.model_name = "Lifecycle test model";
+    model.model_info = std::make_shared<ModelInfo>(std::move(info));
+    init_print({cube(20)}, print, model);
+
+    print.process();
+    ScopedTemporaryFile temp(".gcode");
+    print.export_gcode(temp.string(), nullptr, nullptr);
+    GCodeProcessorResult result;
+    print.export_gcode_from_previous_file(temp.string(), &result);
+
+    const std::string expected_id = std::to_string(print.model().id().id);
+    const std::vector<LifecycleEvent> expected_events = {
+        LifecycleEvent::SliceStarted,
+        LifecycleEvent::SliceGeometryFinished,
+        LifecycleEvent::GCodeExportStarted,
+        LifecycleEvent::GCodeExportFinished,
+        LifecycleEvent::GCodeExportStarted,
+        LifecycleEvent::GCodeExportFinished,
+    };
+    REQUIRE(events.size() == expected_events.size());
+    for (size_t i = 0; i < expected_events.size(); ++i) {
+        CHECK(events[i].event == expected_events[i]);
+        CHECK(events[i].id == expected_id);
+        CHECK(events[i].name == "Lifecycle test model");
+    }
+}
+
+TEST_CASE("Slicing lifecycle event name is empty without model metadata", "[Print][LifecycleEvents]")
+{
+    std::string event_id;
+    std::string event_name = "unset";
+    ScopedLifecycleHook hook([&](LifecycleEvent event, const LifecycleEventContext& ctx) {
+        if (event == LifecycleEvent::SliceStarted) {
+            event_id = ctx.id;
+            event_name = ctx.name;
+        }
+    });
+
+    Print print;
+    Model model;
+    init_print({cube(20)}, print, model);
+    print.process();
+
+    CHECK(event_id == std::to_string(print.model().id().id));
+    CHECK(event_name.empty());
+}
+
+TEST_CASE("Output filenames with numeric statistics fail before slicing finishes", "[Print][Regression]")
+{
+    DynamicPrintConfig config = DynamicPrintConfig::full_print_config();
+    config.set_key_value("filename_format", new ConfigOptionString("{int(total_weight*10) / 10.0}"));
+
+    Print print;
+    Model model;
+    init_print({cube(20)}, print, model, config);
+
+    CHECK_THROWS_AS(print.output_filename(), PlaceholderParserError);
+}
+
 TEST_CASE("Print: {first_object_name} names the first printable object on the plate", "[Print]")
 {
     Model model;

tests/libslic3r/test_3mf.cpp

@@ -17,7 +17,6 @@
 #include <nlohmann/json.hpp>
 
 #include <boost/filesystem/operations.hpp>
-#include <boost/nowide/fstream.hpp>
 #include <boost/algorithm/string/predicate.hpp>
 #include <algorithm>
 
@@ -1462,79 +1461,3 @@ SCENARIO("bbs_3mf_is_published detects only genuinely published 3MFs", "[3mf]")
     }
 }
 
-// Writes a single-entry zip whose central directory carries a zip64 record declaring an
-// uncompressed size beyond what the 32-bit expat buffer API can take, while the deflated
-// payload inflates to only ~64 KiB. Built by hand because miniz never writes a size that
-// disagrees with the data.
-static void write_zip_with_oversized_entry(const std::string& path, const std::string& entry)
-{
-    const std::string xml = "<?xml version=\"1.0\"?><!--" + std::string(65536, 'A') + "--><a/>";
-    size_t comp_len = 0;
-    void*  comp     = tdefl_compress_mem_to_heap(xml.data(), xml.size(), &comp_len, TDEFL_DEFAULT_MAX_PROBES);
-    REQUIRE(comp != nullptr);
-    const std::string deflated(static_cast<const char*>(comp), comp_len);
-    mz_free(comp);
-    const uint32_t crc = static_cast<uint32_t>(mz_crc32(MZ_CRC32_INIT, reinterpret_cast<const unsigned char*>(xml.data()), xml.size()));
-    const uint64_t claimed_size = (uint64_t(1) << 32) + 16;
-
-    std::string out;
-    auto put = [&out](uint64_t v, int bytes) {
-        for (int i = 0; i < bytes; ++i)
-            out.push_back(static_cast<char>((v >> (8 * i)) & 0xFF));
-    };
-    // local file header, with the true sizes
-    put(0x04034b50, 4); put(45, 2); put(0, 2); put(8, 2); put(0, 2); put(0, 2);
-    put(crc, 4); put(deflated.size(), 4); put(xml.size(), 4); put(entry.size(), 2); put(0, 2);
-    out += entry + deflated;
-    // central directory header, sizes deferred to the zip64 extra field
-    const size_t cd_offset = out.size();
-    put(0x02014b50, 4); put(45, 2); put(45, 2); put(0, 2); put(8, 2); put(0, 2); put(0, 2);
-    put(crc, 4); put(0xFFFFFFFF, 4); put(0xFFFFFFFF, 4); put(entry.size(), 2); put(20, 2);
-    put(0, 2); put(0, 2); put(0, 2); put(0, 4); put(0, 4);
-    out += entry;
-    put(0x0001, 2); put(16, 2); put(claimed_size, 8); put(deflated.size(), 8);
-    const size_t cd_size = out.size() - cd_offset;
-    // end of central directory
-    put(0x06054b50, 4); put(0, 2); put(0, 2); put(1, 2); put(1, 2);
-    put(cd_size, 4); put(cd_offset, 4); put(0, 2);
-
-    boost::nowide::ofstream f(path, std::ios::binary);
-    REQUIRE(f.good());
-    f.write(out.data(), static_cast<std::streamsize>(out.size()));
-    REQUIRE(f.good());
-}
-
-TEST_CASE("3MF XML entries declaring more than an int can hold fail to load", "[3mf]") {
-    ScopedTemporaryFile temp(".3mf");
-    const std::string   path = temp.string();
-
-    SECTION("BBS importer") {
-        write_zip_with_oversized_entry(path, "_rels/.rels");
-        Model                     model;
-        DynamicPrintConfig        config;
-        ConfigSubstitutionContext ctxt{ForwardCompatibilitySubstitutionRule::Enable};
-        PlateDataPtrs             plates;
-        std::vector<Preset*>      project_presets;
-        bool                      is_bbl_3mf = false, is_orca_3mf = false;
-        Semver                    file_version;
-        bool                      loaded = true;
-        REQUIRE_NOTHROW(loaded = load_bbs_3mf(path.c_str(), &config, &ctxt, &model, &plates, &project_presets, &is_bbl_3mf,
-                                              &is_orca_3mf, &file_version, nullptr, LoadStrategy::LoadModel | LoadStrategy::LoadConfig));
-        CHECK_FALSE(loaded);
-        release_PlateData_list(plates);
-    }
-    SECTION("PrusaSlicer importer") {
-        write_zip_with_oversized_entry(path, "Metadata/Slic3r_PE_model.config");
-        Model                     model;
-        DynamicPrintConfig        config;
-        ConfigSubstitutionContext ctxt{ForwardCompatibilitySubstitutionRule::Disable};
-        bool                      loaded = true;
-        REQUIRE_NOTHROW(loaded = load_3mf(path.c_str(), config, ctxt, &model, false));
-        CHECK_FALSE(loaded);
-    }
-    SECTION("PrusaSlicer fingerprint probe") {
-        write_zip_with_oversized_entry(path, "3D/3dmodel.model");
-        PrusaFileParser parser;
-        CHECK_FALSE(parser.check_3mf_from_prusa(path));
-    }
-}

tests/libslic3r/test_preset_bundle_loading.cpp

@@ -5405,6 +5405,35 @@ struct ScopedDataDir
     ~ScopedDataDir() { set_data_dir(previous); }
 };
 
+// resources_dir() is process-wide too; system preset lookups scan its profiles directory.
+struct ScopedResourcesDir
+{
+    std::string previous = resources_dir();
+    explicit ScopedResourcesDir(const fs::path &dir) { set_resources_dir(dir.string()); }
+    ~ScopedResourcesDir() { set_resources_dir(previous); }
+};
+
+// An "Acme" vendor under root whose "Acme Printer" inherits extruder_clearance_dist_to_rod from an
+// abstract base, with the printer in a nested sub_path so the name cannot be derived from the file.
+void write_acme_printer_vendor(const fs::path &root, double dist_to_rod)
+{
+    const fs::path machine_dir = root / "Acme" / "machine";
+    fs::create_directories(machine_dir / "nested");
+    std::ofstream((root / "Acme.json").string())
+        << R"({"version":"1.0.0","name":"Acme",)"
+        << R"("machine_model_list":[{"name":"Acme One","sub_path":"machine/model.json"}],"machine_list":[)"
+        << R"({"name":"fdm_acme_common","sub_path":"machine/base.json"},)"
+        << R"({"name":"Acme Printer","sub_path":"machine/nested/printer.json"}]})";
+    std::ofstream((machine_dir / "model.json").string())
+        << R"({"type":"machine_model","name":"Acme One","nozzle_diameter":"0.4"})";
+    std::ofstream((machine_dir / "base.json").string())
+        << R"({"type":"machine","name":"fdm_acme_common","from":"system","instantiation":"false",)"
+        << R"("extruder_clearance_dist_to_rod":")" << dist_to_rod << R"("})";
+    std::ofstream((machine_dir / "nested" / "printer.json").string())
+        << R"({"type":"machine","name":"Acme Printer","from":"system","instantiation":"true","inherits":"fdm_acme_common",)"
+        << R"("printer_model":"Acme One","printer_variant":"0.4"})";
+}
+
 std::string read_file(const fs::path &file)
 {
     std::ifstream in(file.string(), std::ios::binary);
@@ -5482,3 +5511,75 @@ TEST_CASE("Config import confines zip entries, preset names and bundle ids to th
         CHECK_FALSE(any_filename_contains(temp_dir.path(), "bundle-escape"));
     }
 }
+
+TEST_CASE("A system preset resolves by name from the bundled profiles", "[Preset][Bundle]")
+{
+    ScopedTemporaryDir temp_dir;
+    ScopedDataDir      data(temp_dir.path() / "data");
+    ScopedResourcesDir resources(temp_dir.path() / "resources");
+    write_acme_printer_vendor(temp_dir.path() / "resources" / "profiles", 33.);
+
+    PresetBundle       bundle;
+    DynamicPrintConfig config;
+    std::string        error;
+    REQUIRE(bundle.resolve_system_preset(config, Preset::TYPE_PRINTER, "Acme Printer",
+                                         ForwardCompatibilitySubstitutionRule::EnableSilent, error));
+    CHECK(error.empty());
+    CHECK_THAT(config.opt_float("extruder_clearance_dist_to_rod"), Catch::Matchers::WithinAbs(33., 1e-6));
+}
+
+TEST_CASE("A system preset resolves from the data directory copy of its vendor", "[Preset][Bundle]")
+{
+    ScopedTemporaryDir temp_dir;
+    ScopedDataDir      data(temp_dir.path() / "data");
+    ScopedResourcesDir resources(temp_dir.path() / "resources");
+    write_acme_printer_vendor(temp_dir.path() / "resources" / "profiles", 33.);
+    write_acme_printer_vendor(temp_dir.path() / "data" / PRESET_SYSTEM_DIR, 35.);
+
+    PresetBundle       bundle;
+    DynamicPrintConfig config;
+    std::string        error;
+    REQUIRE(bundle.resolve_system_preset(config, Preset::TYPE_PRINTER, "Acme Printer",
+                                         ForwardCompatibilitySubstitutionRule::EnableSilent, error));
+    CHECK_THAT(config.opt_float("extruder_clearance_dist_to_rod"), Catch::Matchers::WithinAbs(35., 1e-6));
+}
+
+TEST_CASE("A system preset resolves from a vendor shipped as its preset cache alone", "[Preset][Bundle]")
+{
+    ScopedTemporaryDir temp_dir;
+    ScopedDataDir      data(temp_dir.path() / "data");
+    ScopedResourcesDir resources(temp_dir.path() / "resources");
+    const fs::path     profiles = temp_dir.path() / "resources" / "profiles";
+    write_acme_printer_vendor(profiles, 33.);
+
+    PresetBundle writer;
+    writer.set_generate_vendor_caches(true);
+    writer.load_vendor_configs_from_json(profiles.string(), "Acme", PresetBundle::LoadSystem,
+                                         ForwardCompatibilitySubstitutionRule::EnableSilent);
+    REQUIRE(fs::exists(profiles / "Acme.opc"));
+    // Release builds ship the cache and drop the profile JSONs, manifest included.
+    fs::remove(profiles / "Acme.json");
+    fs::remove_all(profiles / "Acme");
+
+    PresetBundle       bundle;
+    DynamicPrintConfig config;
+    std::string        error;
+    REQUIRE(bundle.resolve_system_preset(config, Preset::TYPE_PRINTER, "Acme Printer",
+                                         ForwardCompatibilitySubstitutionRule::EnableSilent, error));
+    CHECK_THAT(config.opt_float("extruder_clearance_dist_to_rod"), Catch::Matchers::WithinAbs(33., 1e-6));
+}
+
+TEST_CASE("A system preset no vendor lists is not resolved", "[Preset][Bundle]")
+{
+    ScopedTemporaryDir temp_dir;
+    ScopedDataDir      data(temp_dir.path() / "data");
+    ScopedResourcesDir resources(temp_dir.path() / "resources");
+    write_acme_printer_vendor(temp_dir.path() / "resources" / "profiles", 33.);
+
+    PresetBundle       bundle;
+    DynamicPrintConfig config;
+    std::string        error;
+    CHECK_FALSE(bundle.resolve_system_preset(config, Preset::TYPE_PRINTER, "Unknown Printer",
+                                             ForwardCompatibilitySubstitutionRule::EnableSilent, error));
+    CHECK_FALSE(error.empty());
+}

tests/slic3rutils/CMakeLists.txt

@@ -18,6 +18,7 @@ add_executable(${_TEST_NAME}_tests
     test_plugin_install.cpp
     test_plugin_lifecycle.cpp
     test_plugin_printer_agent.cpp
+    test_printhost.cpp
     test_slicing_pipeline_bindings.cpp
     test_slicing_pipeline_config.cpp
     test_plugin_sort.cpp

tests/slic3rutils/test_printhost.cpp

@@ -0,0 +1,213 @@
+#include <catch2/catch_all.hpp>
+
+#include <nlohmann/json.hpp>
+
+#include "slic3r/Utils/PrintHost.hpp"
+
+using namespace Slic3r;
+
+namespace {
+
+class TestPrintHost : public PrintHost
+{
+public:
+    using PrintHost::format_error;
+
+    const char* get_name() const override { return "Test"; }
+    bool test(wxString&) const override { return true; }
+    wxString get_test_ok_msg() const override { return {}; }
+    wxString get_test_failed_msg(wxString&) const override { return {}; }
+    bool upload(PrintHostUpload, ProgressFn, ErrorFn, InfoFn) const override { return true; }
+    bool has_auto_discovery() const override { return false; }
+    bool can_test() const override { return false; }
+    PrintHostPostUploadActions get_post_upload_actions() const override { return {}; }
+    std::string get_host() const override { return {}; }
+};
+
+std::string format_error(const std::string& body, const std::string& error, unsigned status)
+{
+    return TestPrintHost().format_error(body, error, status).ToStdString();
+}
+
+std::string envelope(int code, const std::string& message, const std::string& traceback)
+{
+    return nlohmann::json{{"error", {{"code", code}, {"message", message}, {"traceback", traceback}}}}.dump();
+}
+
+std::string moonraker_error(int code, const std::string& message, const std::string& detail = {})
+{
+    std::string line = "tornado.web.HTTPError: HTTP " + std::to_string(code) + ": " + message;
+    if (!detail.empty())
+        line += " (" + detail + ")";
+    return envelope(code, message, "Traceback (most recent call last):\n  ...\n" + line + "\n");
+}
+
+// A real Moonraker body for uploading a file that is being printed.
+constexpr const char* k_busy_file_403 =
+    R"JSON({"error": {"code": 403, "message": "Forbidden", "traceback": "Traceback (most recent call last):\n\n  File \"/home/lava/moonraker/moonraker/components/file_manager/file_manager.py\", line 1017, in _finish_gcode_upload\n    can_start = self._handle_operation_check(check_path)\n                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\n\nmoonraker.utils.exceptions.ServerError: File currently in use\n\nDuring handling of the above exception, another exception occurred:\n\nTraceback (most recent call last):\n\n  File \"/home/lava/moonraker/moonraker/components/application.py\", line 1069, in post\n    raise tornado.web.HTTPError(\ntornado.web.HTTPError: HTTP 403: Forbidden (File is loaded, upload not permitted)\n"}})JSON";
+
+} // namespace
+
+TEST_CASE("A Klipper upload error shows its reason instead of a Python traceback", "[PrintHost][Regression]")
+{
+    const std::string msg = format_error(k_busy_file_403, "", 403);
+    INFO("actual: " << msg);
+
+    CHECK(msg == "HTTP 403: Forbidden (File is loaded, upload not permitted)");
+    CHECK_THAT(msg, !Catch::Matchers::ContainsSubstring("Traceback"));
+    CHECK_THAT(msg, !Catch::Matchers::ContainsSubstring("file_manager.py"));
+}
+
+TEST_CASE("The specific cause is recovered from a file endpoint's traceback", "[PrintHost]")
+{
+    SECTION("a plain detail")
+    {
+        const std::string body = moonraker_error(403, "Forbidden", "File is loaded, upload not permitted");
+        CHECK(format_error(body, "", 403) == "HTTP 403: Forbidden (File is loaded, upload not permitted)");
+    }
+
+    SECTION("a detail whose own parentheses nest (a filename)")
+    {
+        const std::string detail = "Directory does not exist (/home/pi/gcodes/plate (1).gcode)";
+        const std::string body   = moonraker_error(400, "Bad Request", detail);
+        CHECK(format_error(body, "", 400) == "HTTP 400: Bad Request (" + detail + ")");
+    }
+
+    SECTION("a detail that contains the reason phrase")
+    {
+        const std::string body = moonraker_error(403, "Forbidden", "Forbidden zone: access denied");
+        CHECK(format_error(body, "", 403) == "HTTP 403: Forbidden (Forbidden zone: access denied)");
+    }
+
+    SECTION("a detail that spans lines")
+    {
+        const std::string detail = "Move out of range\nX=250.000 Y=10.000";
+        const std::string body   = moonraker_error(400, "Bad Request", detail);
+        CHECK(format_error(body, "", 400) == "HTTP 400: Bad Request (" + detail + ")");
+    }
+
+    SECTION("a detail that only repeats the reason phrase is dropped")
+    {
+        const std::string body = moonraker_error(401, "Unauthorized", "Unauthorized");
+        CHECK(format_error(body, "", 401) == "HTTP 401: Unauthorized");
+    }
+}
+
+TEST_CASE("An unhandled exception shows its type and message", "[PrintHost]")
+{
+    const std::string frame = "Traceback (most recent call last):\n"
+                              "  File \"/home/pi/moonraker/moonraker/components/file_manager/file_manager.py\", line 1, in write\n"
+                              "    self._write(data)\n";
+
+    SECTION("a one-line message")
+    {
+        const std::string body = envelope(500, "Internal Server Error", frame + "OSError: [Errno 28] No space left on device\n");
+        CHECK(format_error(body, "", 500) == "HTTP 500: Internal Server Error (OSError: [Errno 28] No space left on device)");
+    }
+
+    SECTION("a message that spans lines")
+    {
+        const std::string body = envelope(500, "Internal Server Error", frame + "ServerError: Klippy request failed\n  see klippy.log\n");
+        CHECK(format_error(body, "", 500) == "HTTP 500: Internal Server Error (ServerError: Klippy request failed\n  see klippy.log)");
+    }
+
+    SECTION("raised while handling an HTTPError with the same code")
+    {
+        const std::string traceback = frame + "tornado.web.HTTPError: HTTP 500: Internal Server Error (Database locked)\n\n"
+                                              "During handling of the above exception, another exception occurred:\n\n" +
+                                      frame + "OSError: [Errno 5] Input/output error\n";
+        const std::string body      = envelope(500, "Internal Server Error", traceback);
+        CHECK(format_error(body, "", 500) == "HTTP 500: Internal Server Error (OSError: [Errno 5] Input/output error)");
+    }
+
+    SECTION("a traceback with no header")
+    {
+        const std::string body = envelope(500, "Internal Server Error", "OSError: [Errno 5] Input/output error");
+        CHECK(format_error(body, "", 500) == "HTTP 500: Internal Server Error (OSError: [Errno 5] Input/output error)");
+    }
+}
+
+TEST_CASE("A reason already complete in message is shown unchanged", "[PrintHost]")
+{
+    SECTION("message is the whole reason, no trailing detail")
+    {
+        const std::string body = moonraker_error(503, "Klippy is not ready");
+        CHECK(format_error(body, "", 503) == "HTTP 503: Klippy is not ready");
+    }
+
+    SECTION("a message that itself contains parentheses is not duplicated")
+    {
+        const std::string reason = "Requested blocks (0-5) are unavailable";
+        const std::string body   = moonraker_error(400, reason);
+        CHECK(format_error(body, "", 400) == "HTTP 400: " + reason);
+    }
+}
+
+TEST_CASE("A Moonraker error with no usable detail shows just the reason phrase", "[PrintHost]")
+{
+    struct Case
+    {
+        const char* name;
+        const char* body;
+        unsigned status;
+        const char* expected;
+    };
+
+    const auto c = GENERATE(
+        Case{"an empty traceback", R"JSON({"error": {"code": 500, "message": "Internal Server Error", "traceback": ""}})JSON", 500,
+             "HTTP 500: Internal Server Error"},
+        Case{"a traceback of only whitespace", R"JSON({"error": {"code": 500, "message": "Internal Server Error", "traceback": "\n \n"}})JSON",
+             500, "HTTP 500: Internal Server Error"});
+
+    DYNAMIC_SECTION(c.name) { CHECK(format_error(c.body, "", c.status) == c.expected); }
+}
+
+TEST_CASE("A percent sign in the reason is not a format specifier", "[PrintHost]")
+{
+    const std::string body = moonraker_error(507, "Insufficient Storage", "disk 100% full");
+    CHECK(format_error(body, "", 507) == "HTTP 507: Insufficient Storage (disk 100% full)");
+}
+
+TEST_CASE("Error bodies that are not a Moonraker envelope are left unchanged", "[PrintHost]")
+{
+    SECTION("OctoPrint's string-valued error member")
+    {
+        const std::string body = R"JSON({"error": "File not found"})JSON";
+        CHECK(format_error(body, "", 404) == "HTTP 404: " + body);
+    }
+
+    SECTION("PrusaLink's top-level message, not under error")
+    {
+        const std::string body = R"JSON({"title": "Conflict", "message": "Printer is printing"})JSON";
+        CHECK(format_error(body, "", 409) == "HTTP 409: " + body);
+    }
+
+    SECTION("a body that is not JSON")
+    {
+        const std::string html = "<html><head><title>502 Bad Gateway</title></head></html>";
+        CHECK(format_error(html, "", 502) == "HTTP 502: " + html);
+    }
+
+    SECTION("an error object with no traceback")
+    {
+        const std::string body = R"JSON({"error": {"code": 500, "message": "Internal Server Error"}})JSON";
+        CHECK(format_error(body, "", 500) == "HTTP 500: " + body);
+    }
+
+    SECTION("an error object whose traceback is null")
+    {
+        const std::string body = R"JSON({"error": {"code": 500, "message": "Internal Server Error", "traceback": null}})JSON";
+        CHECK(format_error(body, "", 500) == "HTTP 500: " + body);
+    }
+
+    SECTION("an envelope whose reason phrase is empty")
+    {
+        const std::string body = envelope(403, "", "Traceback (most recent call last):\nOSError: denied\n");
+        CHECK(format_error(body, "", 403) == "HTTP 403: " + body);
+    }
+
+    SECTION("a transport error with no HTTP status")
+    {
+        CHECK(format_error("", "curl:Could not connect", 0) == "curl:Could not connect");
+    }
+}