Fix config loading for brim_offset

Added a piece of code into handle_legacy to check for aliases.
'.mf3 files won't open 2.4.58.3' #2939

src/libslic3r/Format/3mf.cpp

@@ -3350,13 +3350,14 @@ bool _3MF_Exporter::_add_custom_gcode_per_print_z_file_to_archive( mz_zip_archiv
 //FIXME provide a version of PrusaSlicer that stored the project file (3MF).
 static void handle_legacy_project_loaded(unsigned int version_project_file, DynamicPrintConfig& config)
 {
-    if (! config.has("brim_separation")) {
-        if (auto *opt_elephant_foot   = config.option<ConfigOptionFloat>("first_layer_size_compensation", false); opt_elephant_foot) {
-            // Conversion from older PrusaSlicer which applied brim separation equal to elephant foot compensation.
-            auto *opt_brim_separation = config.option<ConfigOptionFloat>("brim_separation", true);
-            opt_brim_separation->value = opt_elephant_foot->value;
-        }
-    }
+    // SuSi: don't do that. It's hidden behavior.
+    //if (! config.has("brim_separation")) {
+    //    if (auto *opt_elephant_foot   = config.option<ConfigOptionFloat>("first_layer_size_compensation", false); opt_elephant_foot) {
+    //        // Conversion from older PrusaSlicer which applied brim separation equal to elephant foot compensation.
+    //        auto *opt_brim_separation = config.option<ConfigOptionFloat>("brim_separation", true);
+    //        opt_brim_separation->value = -opt_elephant_foot->value;
+    //    }
+    //}
 }
 
 bool is_project_3mf(const std::string& filename)

src/libslic3r/PrintConfig.cpp

@@ -6979,6 +6979,16 @@ void PrintConfigDef::handle_legacy(t_config_option_key &opt_key, std::string &va
     }
 
     if (! print_config_def.has(opt_key)) {
+        //check the aliases
+        for(const auto& entry : print_config_def.options) {
+            for (const std::string& alias : entry.second.aliases) {
+                if (alias == opt_key) {
+                    // translate
+                    opt_key = entry.first;
+                    return;
+                }
+            }
+        }
         opt_key = "";
         return;
     }