Fix of #3889

src/slic3r/GUI/Plater.cpp

@@ -268,7 +268,7 @@ PresetBitmapComboBox(parent, wxSize(15 * wxGetApp().em_unit(), -1)),
     EnableTextChangedEvents(false);
 #endif /* _WIN32 */
     Bind(wxEVT_COMBOBOX, [this](wxCommandEvent &evt) {
-        auto selected_item = this->GetSelection();
+        auto selected_item = evt.GetSelection();
 
         auto marker = reinterpret_cast<Marker>(this->GetClientData(selected_item));
         if (marker >= LABEL_ITEM_MARKER && marker < LABEL_ITEM_MAX) {
@@ -388,9 +388,9 @@ void PresetComboBox::set_label_marker(int item, LabelItemType label_item_type)
     this->SetClientData(item, (void*)label_item_type);
 }
 
-void PresetComboBox::check_selection()
+void PresetComboBox::check_selection(int selection)
 {
-    this->last_selected = GetSelection();
+    this->last_selected = selection;
 }
 
 void PresetComboBox::msw_rescale()
@@ -3627,6 +3627,14 @@ void Plater::priv::on_select_preset(wxCommandEvent &evt)
     auto preset_type = static_cast<Preset::Type>(evt.GetInt());
     auto *combo = static_cast<PresetComboBox*>(evt.GetEventObject());
 
+    // see https://github.com/prusa3d/PrusaSlicer/issues/3889
+    // Under OSX: in case of use of a same names written in different case (like "ENDER" and "Ender"),
+    // m_presets_choice->GetSelection() will return first item, because search in PopupListCtrl is case-insensitive.
+    // So, use GetSelection() from event parameter 
+    // But in this function we couldn't use evt.GetSelection(), because m_commandInt is used for preset_type
+    // Thus, get selection in this way:
+    int selection = combo->FindString(evt.GetString(), true);
+
     auto idx = combo->get_extruder_idx();
 
     //! Because of The MSW and GTK version of wxBitmapComboBox derived from wxComboBox,
@@ -3637,7 +3645,7 @@ void Plater::priv::on_select_preset(wxCommandEvent &evt)
     //!     combo->GetStringSelection().ToUTF8().data());
 
     const std::string preset_name = wxGetApp().preset_bundle->get_preset_name_by_alias(preset_type, 
-        Preset::remove_suffix_modified(combo->GetString(combo->GetSelection()).ToUTF8().data()));
+        Preset::remove_suffix_modified(combo->GetString(selection).ToUTF8().data()));
 
     if (preset_type == Preset::TYPE_FILAMENT) {
         wxGetApp().preset_bundle->set_filament_preset(idx, preset_name);

src/slic3r/GUI/Plater.hpp

@@ -71,7 +71,7 @@ public:
     void set_extruder_idx(const int extr_idx)   { extruder_idx = extr_idx; }
     int  get_extruder_idx() const               { return extruder_idx; }
     int  em_unit() const                        { return m_em_unit; }
-    void check_selection();
+    void check_selection(int selection);
 
     void msw_rescale();
 

src/slic3r/GUI/Preset.cpp

@@ -1253,7 +1253,7 @@ void PresetCollection::update_plater_ui(GUI::PresetComboBox *ui)
 
     ui->SetSelection(selected_preset_item);
     ui->SetToolTip(tooltip.IsEmpty() ? ui->GetString(selected_preset_item) : tooltip);
-    ui->check_selection();
+    ui->check_selection(selected_preset_item);
     ui->Thaw();
 
     // Update control min size after rescale (changed Display DPI under MSW)

src/slic3r/GUI/PresetBundle.cpp

@@ -1737,7 +1737,7 @@ void PresetBundle::update_plater_filament_ui(unsigned int idx_extruder, GUI::Pre
 
 	ui->SetSelection(selected_preset_item);
 	ui->SetToolTip(tooltip.IsEmpty() ? ui->GetString(selected_preset_item) : tooltip);
-    ui->check_selection();
+    ui->check_selection(selected_preset_item);
     ui->Thaw();
 
     // Update control min size after rescale (changed Display DPI under MSW)

src/slic3r/GUI/Tab.cpp

@@ -229,7 +229,13 @@ void Tab::create_preset_tab()
         //! but the OSX version derived from wxOwnerDrawnCombo, instead of:
         //! select_preset(m_presets_choice->GetStringSelection().ToUTF8().data()); 
         //! we doing next:
-        int selected_item = m_presets_choice->GetSelection();
+        // int selected_item = m_presets_choice->GetSelection();
+
+        // see https://github.com/prusa3d/PrusaSlicer/issues/3889
+        // Under OSX: in case of use of a same names written in different case (like "ENDER" and "Ender")
+        // m_presets_choice->GetSelection() will return first item, because search in PopupListCtrl is case-insensitive.
+        // So, use GetSelection() from event parameter 
+        int selected_item = e.GetSelection();
         if (m_selected_preset_item == size_t(selected_item) && !m_presets->current_is_dirty())
             return;
         if (selected_item >= 0) {