fix: Compare Presets crash on filaments with different variant counts (#16176)

src/slic3r/GUI/ConfigValueFormatter.cpp

@@ -53,6 +53,8 @@ wxString get_string_from_enum(const std::string& opt_key, const DynamicPrintConf
             }
         return _L("Undefined");
     }
+    if (val < 0 || val >= int(names.size()))
+        return _L("Undefined");
     return from_u8(_utf8(names[val]));
 }
 
@@ -215,6 +217,8 @@ wxString get_string_value(const std::string& opt_key, const DynamicPrintConfig&
             ;
     }
     case coEnums: {
+        if (!opt_vector || opt_idx >= opt_vector->size())
+            return _L("Undefined");
         return get_string_from_enum(pure_key, config,
             pure_key == "top_surface_pattern" ||
             pure_key == "bottom_surface_pattern" ||

tests/slic3rutils/CMakeLists.txt

@@ -2,6 +2,7 @@ get_filename_component(_TEST_NAME ${CMAKE_CURRENT_LIST_DIR} NAME)
 add_executable(${_TEST_NAME}_tests
     ${_TEST_NAME}_tests_main.cpp
     test_bambu_filament_ids.cpp
+    test_config_value_formatter.cpp
     test_creality_cfs_match.cpp
     test_dev_mapping.cpp
     test_filament_bitmap_utils.cpp

tests/slic3rutils/test_config_value_formatter.cpp

@@ -0,0 +1,40 @@
+#include <catch2/catch_test_macros.hpp>
+
+#include <string>
+
+#include "libslic3r/Config.hpp"
+#include "libslic3r/PrintConfig.hpp"
+#include "slic3r/GUI/ConfigValueFormatter.hpp"
+
+using namespace Slic3r;
+using namespace Slic3r::GUI;
+
+TEST_CASE("An enum vector index past the end of the vector reads as undefined", "[ConfigValueFormatter][Regression]")
+{
+    const std::string key = "filament_retract_lift_enforce";
+    const ConfigOptionDef* def = print_config_def.get(key);
+    DynamicPrintConfig config;
+    config.set_key_value(key, new ConfigOptionEnumsGenericNullable(def->enum_keys_map, 1, ConfigOptionEnumsGenericNullable::nil_value()));
+
+    CHECK(get_string_value(key + "#1", config) == "Undefined");
+}
+
+TEST_CASE("An enum vector index inside the vector reads as its label", "[ConfigValueFormatter]")
+{
+    const std::string key = "filament_retract_lift_enforce";
+    const ConfigOptionDef* def = print_config_def.get(key);
+    DynamicPrintConfig config;
+    config.set_key_value(key, new ConfigOptionEnumsGenericNullable(def->enum_keys_map, 1, def->enum_keys_map->at("Top Only")));
+
+    CHECK(get_string_value(key + "#0", config).utf8_string() == "Top Only");
+}
+
+TEST_CASE("An enum value outside the label list reads as undefined", "[ConfigValueFormatter]")
+{
+    const std::string key = "filament_retract_lift_enforce";
+    const ConfigOptionDef* def = print_config_def.get(key);
+    DynamicPrintConfig config;
+    config.set_key_value(key, new ConfigOptionEnumsGenericNullable(def->enum_keys_map, 1, int(def->enum_labels.size())));
+
+    CHECK(get_string_value(key + "#0", config) == "Undefined");
+}