From bb6c3a2d794bb2c570056ed91a3684b17136c6b8 Mon Sep 17 00:00:00 2001
From: remi durand <remi-j.durand@thalesgroup.com>
Date: Thu, 24 Jun 2021 18:50:27 +0200
Subject: [PATCH] fix Z offset: fix crash (comes from commit
 0a65e1b0d6a234bb9c9d58047940bed85260d700) fix slicing preview also fix a
 toolchange missing (just notifying the writer) supermerill/SuperSlicer#1347

---
 src/libslic3r/GCode.cpp        | 6 +++---
 src/slic3r/GUI/GUI_Preview.cpp | 4 ++--
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/libslic3r/GCode.cpp b/src/libslic3r/GCode.cpp
index 5d019fdb1..efcf9610b 100644
--- a/src/libslic3r/GCode.cpp
+++ b/src/libslic3r/GCode.cpp
@@ -1451,7 +1451,7 @@ void GCode::_do_export(Print& print, FILE* file, ThumbnailsGeneratorCallback thu
                 for (LayerToPrint &ltp : layers_to_print) {
                     std::vector<LayerToPrint> lrs;
                     lrs.emplace_back(std::move(ltp));
-                    this->process_layer(file, print, print.m_print_statistics, lrs, tool_ordering.tools_for_layer(ltp.print_z() + print.config().z_offset), nullptr, *print_object_instance_sequential_active - object.instances().data());
+                    this->process_layer(file, print, print.m_print_statistics, lrs, tool_ordering.tools_for_layer(ltp.print_z()), nullptr, *print_object_instance_sequential_active - object.instances().data());
                     print.throw_if_canceled();
                 }
 #ifdef HAS_PRESSURE_EQUALIZER
@@ -4059,7 +4059,7 @@ std::string GCode::set_extruder(uint16_t extruder_id, double print_z, bool no_to
         }
         if (!no_toolchange) {
             gcode+=toolchange(extruder_id, print_z);
-        }
+        }else m_writer.toolchange(extruder_id);
         return gcode;
     }
 
@@ -4094,7 +4094,7 @@ std::string GCode::set_extruder(uint16_t extruder_id, double print_z, bool no_to
 
     if (!no_toolchange) {
         gcode += toolchange(extruder_id, print_z);
-    }
+    }else m_writer.toolchange(extruder_id);
 
     // Set the temperature if the wipe tower didn't (not needed for non-single extruder MM)
     // supermerill change: try to set the good temp, because the wipe tower don't use the gcode writer and so can write wrong stuff.
diff --git a/src/slic3r/GUI/GUI_Preview.cpp b/src/slic3r/GUI/GUI_Preview.cpp
index 498b2ff34..d6e8cc242 100644
--- a/src/slic3r/GUI/GUI_Preview.cpp
+++ b/src/slic3r/GUI/GUI_Preview.cpp
@@ -663,7 +663,7 @@ wxBoxSizer* Preview::create_layers_slider_sizer()
         Info custom_gcode_per_print_z = m_layers_slider->GetTicksValues();
         //remove z-shift from gcode output
         const float z_shift = wxGetApp().preset_bundle->printers.get_edited_preset().config.opt_float("z_offset");
-        if (can_display_gcode() && z_shift != 0) {
+        if (can_display_gcode() && z_shift != 0 && ForceState::ForceExtrusions != current_force_state) {
             for (CustomGCode::Item& tick : custom_gcode_per_print_z.gcodes) {
                 tick.print_z -= z_shift;
             }
@@ -751,7 +751,7 @@ void Preview::update_layers_slider(const std::vector<double>& layers_z, bool kee
     {
         //add z-shift from gcode output
         const float z_shift = wxGetApp().preset_bundle->printers.get_edited_preset().config.opt_float("z_offset");
-        if (can_display_gcode() && z_shift != 0) {
+        if (can_display_gcode() && z_shift != 0 && ForceState::ForceExtrusions != current_force_state) {
             for (CustomGCode::Item& tick : ticks_info_from_model.gcodes) {
                 tick.print_z += z_shift;
             }