Clamp Ironing Line Spacing to a Usable Minimum

An ironing line spacing of 0 reached the fillers from a 3MF, the CLI or
the per-filament override, which has no GUI guard. Concentric ironing
then never finished slicing, because a zero inset never shrinks the
region, and rectilinear ironing was silently dropped. Tiny positive
values produced an unprintable number of lines.

Top surface and support ironing now clamp the spacing to the 0.05 mm
floor the process GUI guard already enforces, so these configurations
iron at that spacing. Spacings at or above the floor, including every
shipped profile, are unchanged. The concentric filler also returns early
on a non-positive step so no other caller can hang it, and the filament
settings page now resets a too-small override the same way the process
page does.

src/libslic3r/Fill/Fill.cpp

@@ -1692,9 +1692,9 @@ void Layer::make_ironing()
 				ironing_params.just_infill 	= false;
 				// ORCA: Get filament-specific overrides if configured, otherwise use process values
 				size_t extruder_idx = ironing_params.extruder - 1;
-				ironing_params.line_spacing = (!config.filament_ironing_spacing.is_nil(extruder_idx)
+				ironing_params.line_spacing = std::max(IRONING_SPACING_MIN, !config.filament_ironing_spacing.is_nil(extruder_idx)
 					? config.filament_ironing_spacing.get_at(extruder_idx)
-					: config.ironing_spacing);
+					: config.ironing_spacing.value);
                 ironing_params.inset = (!config.filament_ironing_inset.is_nil(extruder_idx)
 					? config.filament_ironing_inset.get_at(extruder_idx)
 					: config.ironing_inset);

src/libslic3r/Fill/FillConcentric.cpp

@@ -22,6 +22,9 @@ void FillConcentric::_fill_surface_single(
     
     coord_t min_spacing = scale_(this->spacing) * params.multiline;
     coord_t distance = coord_t(min_spacing / params.density);
+    // A non-positive step never shrinks the region, so the inset loop below would not end.
+    if (min_spacing <= 0 || distance <= 0)
+        return;
     
     if (params.density > 0.9999f && !params.dont_adjust) {
         distance = this->_adjust_solid_spacing(bounding_box.size()(0), distance);
@@ -108,6 +111,8 @@ void FillConcentric::_fill_surface_single(const FillParams& params,
     // no rotation is supported for this infill pattern
     Point   bbox_size = expolygon.contour.bounding_box().size();
     coord_t min_spacing = scaled<coord_t>(this->spacing);
+    if (min_spacing <= 0)
+        return;
 
     if (params.density > 0.9999f && !params.dont_adjust) {
         coord_t                loops_count = std::max(bbox_size.x(), bbox_size.y()) / min_spacing + 1;

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/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/libslic3r/PrintConfig.hpp

@@ -178,6 +178,10 @@ enum class IroningType {
     Count,
 };
 
+// Smallest usable ironing line spacing. Anything tighter yields an unprintable number of lines,
+// and zero stops the fillers from making progress.
+constexpr double IRONING_SPACING_MIN = 0.05;
+
 //BBS
 enum class WallInfillOrder {
     InnerOuterInfill,

src/libslic3r/Support/SupportParameters.hpp

@@ -64,7 +64,7 @@ struct SupportParameters {
 
         this->ironing = object_config.support_ironing;
         this->ironing_flow = support_material_interface_flow.with_height(support_material_interface_flow.height() * 0.01 * object_config.support_ironing_flow.value);
-        this->ironing_spacing = object_config.support_ironing_spacing;
+        this->ironing_spacing = std::max(IRONING_SPACING_MIN, object_config.support_ironing_spacing.value);
         this->ironing_pattern = object_config.support_ironing_pattern;
 
         // Calculate a minimum support layer height as a minimum over all extruders, but not smaller than 10um.

src/slic3r/GUI/ConfigManipulation.cpp

@@ -210,6 +210,30 @@ void ConfigManipulation::check_filament_max_volumetric_speed(DynamicPrintConfig
 
 }
 
+void ConfigManipulation::check_filament_ironing_spacing(DynamicPrintConfig *config)
+{
+    const auto *opt = config->option<ConfigOptionFloatsNullable>("filament_ironing_spacing");
+    if (opt == nullptr)
+        return;
+    std::vector<double> values = opt->values;
+    bool                reset  = false;
+    for (size_t i = 0; i < values.size(); ++i)
+        if (!opt->is_nil(i) && values[i] < IRONING_SPACING_MIN) {
+            values[i] = 0.1;
+            reset     = true;
+        }
+    if (!reset)
+        return;
+    const wxString     msg_text = _(L("Ironing spacing too small\nIt has been reset to 0.1"));
+    MessageDialog      dialog(nullptr, msg_text, "", wxICON_WARNING | wxOK);
+    DynamicPrintConfig new_conf = *config;
+    is_msg_dlg_already_exist    = true;
+    dialog.ShowModal();
+    new_conf.set_key_value("filament_ironing_spacing", new ConfigOptionFloatsNullable(values));
+    apply(config, &new_conf);
+    is_msg_dlg_already_exist = false;
+}
+
 void ConfigManipulation::check_chamber_temperature(DynamicPrintConfig* config)
 {
    bool support_chamber_temp_control=GUI::wxGetApp().preset_bundle->printers.get_selected_preset().config.opt_bool("support_chamber_temp_control");
@@ -332,7 +356,7 @@ void ConfigManipulation::update_print_fff_config(DynamicPrintConfig* config, con
     }
 
     //BBS: ironing_spacing shouldn't be too small or equal to zero
-    if (config->opt_float("ironing_spacing") < 0.05)
+    if (config->opt_float("ironing_spacing") < IRONING_SPACING_MIN)
     {
         const wxString msg_text = _(L("Ironing spacing too small\nIt has been reset to 0.1"));
         MessageDialog dialog(nullptr, msg_text, "", wxICON_WARNING | wxOK);
@@ -343,7 +367,7 @@ void ConfigManipulation::update_print_fff_config(DynamicPrintConfig* config, con
         apply(config, &new_conf);
         is_msg_dlg_already_exist = false;
     }
-    if (config->opt_float("support_ironing_spacing") < 0.05)
+    if (config->opt_float("support_ironing_spacing") < IRONING_SPACING_MIN)
     {
         const wxString msg_text = _(L("Ironing spacing too small\nIt has been reset to 0.1"));
         MessageDialog dialog(nullptr, msg_text, "", wxICON_WARNING | wxOK);

src/slic3r/GUI/ConfigManipulation.hpp

@@ -84,6 +84,7 @@ public:
     void    check_nozzle_temperature_initial_layer_range(DynamicPrintConfig* config);
     void    check_adaptive_pressure_advance_model(DynamicPrintConfig* config);
     void    check_filament_max_volumetric_speed(DynamicPrintConfig *config);
+    void    check_filament_ironing_spacing(DynamicPrintConfig *config);
     void    check_chamber_temperature(DynamicPrintConfig* config);
     void    check_chamber_minimal_temperature(DynamicPrintConfig* config);
     bool    check_layer_height(DynamicPrintConfig* config);

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/GUI/Tab.cpp

@@ -4905,6 +4905,7 @@ void TabFilament::update()
         return; // ys_FIXME
 
     m_config_manipulation.check_filament_max_volumetric_speed(m_config);
+    m_config_manipulation.check_filament_ironing_spacing(m_config);
 
     m_update_cnt++;
 

tests/fff_print/test_fill.cpp

@@ -747,6 +747,61 @@ TEST_CASE("A region with ironing turned off is never ironed", "[Fill]")
     REQUIRE(Layer::choose_ironing_extruder(cfg, spiral_mode, /*is_topmost_layer=*/true) == -1);
 }
 
+// Ironing path count and total length in mm, over the whole object.
+static std::pair<size_t, double> ironing_extent(const Print &print)
+{
+    size_t paths  = 0;
+    double length = 0.;
+    for (const Layer *layer : print.objects().front()->layers())
+        for (const LayerRegion *region : layer->regions())
+            for (const ExtrusionEntity *entity : region->fills.flatten().entities)
+                if (ironing_role(entity->role())) {
+                    ++paths;
+                    length += unscale<double>(entity->length());
+                }
+    return {paths, length};
+}
+
+TEST_CASE("Ironing spacing below the minimum irons at the minimum spacing", "[Fill]")
+{
+    const std::string pattern      = GENERATE("rectilinear", "concentric");
+    const bool        via_filament = GENERATE(false, true);
+    const double      spacing      = GENERATE(0., 0.001);
+    CAPTURE(pattern, via_filament, spacing);
+
+    auto ironing_for = [&pattern, via_filament](double spacing) {
+        DynamicPrintConfig config = DynamicPrintConfig::full_print_config();
+        config.set_deserialize_strict({{"ironing_type", "top"},
+                                       {"ironing_pattern", pattern},
+                                       {"layer_height", 0.2}});
+        // The filament override replaces the process spacing, which stays at a usable value.
+        if (via_filament)
+            config.set_deserialize_strict({{"ironing_spacing", 0.1}, {"filament_ironing_spacing", spacing}});
+        else
+            config.set_deserialize_strict({{"ironing_spacing", spacing}});
+        Print print;
+        Slic3r::Test::init_and_process_print({Slic3r::Test::cube(20)}, print, config);
+        return ironing_extent(print);
+    };
+
+    const std::pair<size_t, double> clamped = ironing_for(spacing);
+    const std::pair<size_t, double> minimum = ironing_for(IRONING_SPACING_MIN);
+    REQUIRE(minimum.first > 0);
+    CHECK(clamped.first == minimum.first);
+    CHECK_THAT(clamped.second, Catch::Matchers::WithinRel(minimum.second, 1e-9));
+}
+
+TEST_CASE("Concentric fill at zero spacing returns without paths", "[Fill]")
+{
+    std::unique_ptr<Fill> filler(Fill::new_from_type(ipConcentric));
+    filler->spacing      = 0.;
+    filler->bounding_box = BoundingBox(Point(0, 0), Point::new_scale(10, 10));
+    FillParams params;
+    params.density = 1.f;
+    Surface surface(stTop, ExPolygon({Point(0, 0), Point::new_scale(10, 0), Point::new_scale(10, 10), Point::new_scale(0, 10)}));
+    CHECK(filler->fill_surface(&surface, params).empty());
+}
+
 TEST_CASE("Solid infill direction offsets every layer when no template is set", "[Fill]")
 {
     auto angles_for = [](int direction) {

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;