2.0 Fix for bad Pause extruder position resuming (#9029)

Marlin/src/feature/pause.cpp

@@ -37,6 +37,10 @@
 #include "../module/printcounter.h"
 #include "../module/temperature.h"
 
+#if ENABLED(FWRETRACT)
+  #include "../feature/fwretract.h"
+#endif
+
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
   #include "../feature/runout.h"
 #endif
@@ -329,13 +333,26 @@ void resume_print(const float &load_length/*=0*/, const float &initial_extrude_l
     lcd_advanced_pause_show_message(ADVANCED_PAUSE_MESSAGE_RESUME);
   #endif
 
-  // Set extruder to saved position
-  planner.set_e_position_mm((current_position[E_AXIS] = resume_position[E_AXIS]));
+  // Intelligent resuming
+  #if ENABLED(FWRETRACT)
+    // If retracted before goto pause
+    if (fwretract.retracted[active_extruder])
+      do_pause_e_move(-fwretract.retract_length, fwretract.retract_feedrate_mm_s);
+  #else
+    // If resume_position negative
+    if (resume_position[E_AXIS] < 0) do_pause_e_move(resume_position[E_AXIS], PAUSE_PARK_RETRACT_FEEDRATE);
+  #endif
 
   // Move XY to starting position, then Z
   do_blocking_move_to_xy(resume_position[X_AXIS], resume_position[Y_AXIS], NOZZLE_PARK_XY_FEEDRATE);
+
+  // Set Z_AXIS to saved position
   do_blocking_move_to_z(resume_position[Z_AXIS], NOZZLE_PARK_Z_FEEDRATE);
 
+  // Now all extrusion positions are resumed and ready to be confirmed
+  // Set extruder to saved position
+  planner.set_e_position_mm(destination[E_AXIS] = current_position[E_AXIS] = resume_position[E_AXIS]);
+
   #if ENABLED(FILAMENT_RUNOUT_SENSOR)
     filament_ran_out = false;
   #endif