From 498779d7ab1c8d96d2a99edc3d288f53bb0d63e2 Mon Sep 17 00:00:00 2001
From: Phil Hord <hordp@cisco.com>
Date: Thu, 24 Oct 2013 19:37:39 -0400
Subject: [PATCH] gcode-process.c: fix HEATER_EXTRUDER reference.

A rare combination of factors makes this code assume HEATER_EXTRUDER
always exists, when that is not necessarily so.  Add the normal
guard around it.
---
 gcode_process.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/gcode_process.c b/gcode_process.c
index 3e0bfa3..0d4e556 100644
--- a/gcode_process.c
+++ b/gcode_process.c
@@ -715,9 +715,11 @@ void process_gcode_command() {
 				//? --- M136: PRINT PID settings to host ---
 				//? Undocumented.
 				//? This comand is only available in DEBUG builds.
+        #ifdef HEATER_EXTRUDER
 				if ( ! next_target.seen_P)
 					next_target.P = HEATER_EXTRUDER;
 				heater_print(next_target.P);
+        #endif
 				break;
 			#endif