From ca5a8ea827e99a681fa1dfc7e8d4949ef0c45d9a Mon Sep 17 00:00:00 2001
From: Scott Lahteine <github@thinkyhead.com>
Date: Mon, 8 Jun 2020 17:28:25 -0500
Subject: [PATCH] Add G-code "backspace" support

---
 Marlin/src/gcode/queue.cpp | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/Marlin/src/gcode/queue.cpp b/Marlin/src/gcode/queue.cpp
index 24d1d2cf67..d87166d979 100644
--- a/Marlin/src/gcode/queue.cpp
+++ b/Marlin/src/gcode/queue.cpp
@@ -387,9 +387,15 @@ inline void process_stream_char(const char c, uint8_t &sis, char (&buff)[MAX_CMD
     }
   #endif
 
-  buff[ind++] = c;
-  if (ind >= MAX_CMD_SIZE - 1)
-    sis = PS_EOL;               // Skip the rest on overflow
+  // Backspace erases previous characters
+  if (c == 0x08) {
+    if (ind) buff[--ind] = '\0';
+  }
+  else {
+    buff[ind++] = c;
+    if (ind >= MAX_CMD_SIZE - 1)
+      sis = PS_EOL;             // Skip the rest on overflow
+  }
 }
 
 /**