From 46776de90b71147f2a5e4959bd901322dc89a5a8 Mon Sep 17 00:00:00 2001
From: Scott Lahteine <github@thinkyhead.com>
Date: Tue, 28 Nov 2017 17:25:14 -0600
Subject: [PATCH] Fix M290 boolval bug

Fix #8577
---
 Marlin/Marlin_main.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Marlin/Marlin_main.cpp b/Marlin/Marlin_main.cpp
index 39dc5dc44..51db7ccb2 100644
--- a/Marlin/Marlin_main.cpp
+++ b/Marlin/Marlin_main.cpp
@@ -9346,7 +9346,7 @@ inline void gcode_M226() {
           const float offs = constrain(parser.value_axis_units((AxisEnum)a), -2, 2);
           thermalManager.babystep_axis((AxisEnum)a, offs * planner.axis_steps_per_mm[a]);
           #if ENABLED(BABYSTEP_ZPROBE_OFFSET)
-            if (a == Z_AXIS && parser.boolval('P', true)) mod_zprobe_zoffset(offs);
+            if (a == Z_AXIS && (!parser.seen('P') || parser.value_bool())) mod_zprobe_zoffset(offs);
           #endif
         }
     #else
@@ -9354,7 +9354,7 @@ inline void gcode_M226() {
         const float offs = constrain(parser.value_axis_units(Z_AXIS), -2, 2);
         thermalManager.babystep_axis(Z_AXIS, offs * planner.axis_steps_per_mm[Z_AXIS]);
         #if ENABLED(BABYSTEP_ZPROBE_OFFSET)
-          if (parser.boolval('P', true)) mod_zprobe_zoffset(offs);
+          if (!parser.seen('P') || parser.value_bool()) mod_zprobe_zoffset(offs);
         #endif
       }
     #endif