Avoid collisions when moving to scarf joint start

Fixes SoftFever#7191

src/libslic3r/GCode.cpp

@@ -4752,8 +4752,13 @@ std::string GCode::extrude_loop(ExtrusionLoop loop, std::string description, dou
         ExtrusionLoopSloped new_loop(paths, seam_gap, slope_min_length, slope_max_segment_length, start_slope_ratio, loop.loop_role());
         new_loop.clip_slope(seam_gap);
 
-        // Then extrude it
-        for (const auto& p : new_loop.get_all_paths()) {
+        const auto seam_slope_paths = new_loop.get_all_paths();
+	const auto & seam_slope_start = seam_slope_paths[0]->first_point();
+	// Orca: First move to XY position, not Z, to avoid colliding with previous extrusions
+        gcode += m_writer.extrude_to_xy(this->point_to_gcode(seam_slope_start), 0,"horizontal before down to avoid collision",true);
+
+    	// Then extrude it
+        for (const auto& p : seam_slope_paths) {
             gcode += this->_extrude(*p, description, speed_for_path(*p));
             // Orca: Adaptive PA - dont adapt PA after the first pultipath extrusion is completed
             // as we have already set the PA value to the average flow over the totality of the path