From ce142afddae60aad7ce6f7fb2d223613607b700d Mon Sep 17 00:00:00 2001
From: Scott Lahteine <sourcetree@thinkyhead.com>
Date: Fri, 24 Apr 2015 20:13:01 -0700
Subject: [PATCH] G4 shows status message only if no message is set already

- Address issue raised in #1961
---
 Marlin/Marlin_main.cpp | 5 +++--
 Marlin/ultralcd.cpp    | 2 ++
 Marlin/ultralcd.h      | 1 +
 3 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/Marlin/Marlin_main.cpp b/Marlin/Marlin_main.cpp
index a09ef4907..e1a9cd6e0 100644
--- a/Marlin/Marlin_main.cpp
+++ b/Marlin/Marlin_main.cpp
@@ -1740,14 +1740,15 @@ inline void gcode_G2_G3(bool clockwise) {
 inline void gcode_G4() {
   millis_t codenum = 0;
 
-  LCD_MESSAGEPGM(MSG_DWELL);
-
   if (code_seen('P')) codenum = code_value_long(); // milliseconds to wait
   if (code_seen('S')) codenum = code_value_long() * 1000; // seconds to wait
 
   st_synchronize();
   refresh_cmd_timeout();
   codenum += previous_cmd_ms;  // keep track of when we started waiting
+
+  if (!lcd_hasstatus()) LCD_MESSAGEPGM(MSG_DWELL);
+
   while (millis() < codenum) {
     manage_heater();
     manage_inactivity();
diff --git a/Marlin/ultralcd.cpp b/Marlin/ultralcd.cpp
index c96f09899..03da2366b 100644
--- a/Marlin/ultralcd.cpp
+++ b/Marlin/ultralcd.cpp
@@ -1418,6 +1418,8 @@ void set_utf_strlen(char *s, uint8_t n) {
   s[i] = 0;
 }
 
+bool lcd_hasstatus() { return (lcd_status_message[0] != '\0'); }
+
 void lcd_setstatus(const char* message, bool persist) {
   if (lcd_status_message_level > 0) return;
   strncpy(lcd_status_message, message, 3*LCD_WIDTH);
diff --git a/Marlin/ultralcd.h b/Marlin/ultralcd.h
index b8d5cba8a..97d939fa3 100644
--- a/Marlin/ultralcd.h
+++ b/Marlin/ultralcd.h
@@ -8,6 +8,7 @@
   int lcd_strlen_P(const char *s);
   void lcd_update();
   void lcd_init();
+  bool lcd_hasstatus();
   void lcd_setstatus(const char* message, const bool persist=false);
   void lcd_setstatuspgm(const char* message, const uint8_t level=0);
   void lcd_setalertstatuspgm(const char* message);