🚸 Filter 'G29 S0' in ABL

Marlin/src/gcode/bedlevel/abl/G29.cpp

@@ -393,6 +393,7 @@ G29_TYPE GcodeSuite::G29() {
     #if ABL_USES_GRID
 
       xy_probe_feedrate_mm_s = MMM_TO_MMS(parser.linearval('S', XY_PROBE_FEEDRATE));
+      if (xy_probe_feedrate_mm_s == 0) xy_probe_feedrate_mm_s = XY_PROBE_FEEDRATE; // Don't let "UBL Save Slot #0" break G29
 
       const float x_min = probe.min_x(), x_max = probe.max_x(),
                   y_min = probe.min_y(), y_max = probe.max_y();

Marlin/src/lcd/extui/ui_api.cpp

@@ -1003,7 +1003,7 @@ namespace ExtUI {
             feedrate_mm_s = MMM_TO_MMS(Z_PROBE_FEEDRATE_FAST);
             destination.set(current_position.x, current_position.y, Z_CLEARANCE_BETWEEN_PROBES);
             prepare_line_to_destination();
-            feedrate_mm_s = XY_PROBE_FEEDRATE_MM_S;
+            if (XY_PROBE_FEEDRATE_MM_S) feedrate_mm_s = XY_PROBE_FEEDRATE_MM_S;
             destination.set(x_target, y_target);
             prepare_line_to_destination();
           }