From dad901797cc311f74d8020d2eb41180ecf759f15 Mon Sep 17 00:00:00 2001
From: gralco <kuzmenko@alephobjects.com>
Date: Mon, 15 Feb 2016 08:51:33 -0700
Subject: [PATCH] Ensure that the rx_buffer does not truncate G-Code and tell
 the host if it does (once)

Conflicts:
	Marlin/MarlinSerial.cpp

Report that the RX buffer was filled once

Ring buffer overflow also checks for \r and :

nonsense that will be squashed

Conflicts:
	Marlin/Marlin.h
	Marlin/MarlinSerial.cpp
	Marlin/Marlin_main.cpp
---
 Marlin/Marlin.h         |  2 ++
 Marlin/MarlinSerial.cpp | 49 +++++++++++++++++++++++++++++------------
 Marlin/Marlin_main.cpp  | 12 ++++++++++
 Marlin/language.h       |  1 +
 4 files changed, 50 insertions(+), 14 deletions(-)

diff --git a/Marlin/Marlin.h b/Marlin/Marlin.h
index 8819b3fb8fe9..64a96c4d88fc 100644
--- a/Marlin/Marlin.h
+++ b/Marlin/Marlin.h
@@ -268,6 +268,7 @@ inline void refresh_cmd_timeout() { previous_cmd_ms = millis(); }
   #define CRITICAL_SECTION_END    SREG = _sreg;
 #endif
 
+extern boolean comment_mode;
 extern bool axis_relative_modes[];
 extern int feedrate_multiplier;
 extern bool volumetric_enabled;
@@ -276,6 +277,7 @@ extern float filament_size[EXTRUDERS]; // cross-sectional area of filament (in m
 extern float volumetric_multiplier[EXTRUDERS]; // reciprocal of cross-sectional area of filament (in square millimeters), stored this way to reduce computational burden in planner
 extern float current_position[NUM_AXIS];
 extern float home_offset[3]; // axis[n].home_offset
+extern bool rxbuf_filled;
 extern float min_pos[3]; // axis[n].min_pos
 extern float max_pos[3]; // axis[n].max_pos
 extern bool axis_known_position[3]; // axis[n].is_known
diff --git a/Marlin/MarlinSerial.cpp b/Marlin/MarlinSerial.cpp
index e6362fc7c78c..61049ba86922 100644
--- a/Marlin/MarlinSerial.cpp
+++ b/Marlin/MarlinSerial.cpp
@@ -40,20 +40,41 @@
   ring_buffer rx_buffer  =  { { 0 }, 0, 0 };
 #endif
 
-FORCE_INLINE void store_char(unsigned char c) {
-  CRITICAL_SECTION_START;
-    uint8_t h = rx_buffer.head;
-    uint8_t i = (uint8_t)(h + 1)  & (RX_BUFFER_SIZE - 1);
-
-    // if we should be storing the received character into the location
-    // just before the tail (meaning that the head would advance to the
-    // current location of the tail), we're about to overflow the buffer
-    // and so we don't write the character or advance the head.
-    if (i != rx_buffer.tail) {
-      rx_buffer.buffer[h] = c;
-      rx_buffer.head = i;
-    }
-  CRITICAL_SECTION_END;
+bool rxbuf_filled = false;
+
+FORCE_INLINE void store_char(unsigned char c)
+{
+  static bool overflow = false;
+  if(overflow && !(c == '\n' || c == '\r' || (c == ':' && comment_mode == false)))
+    return;
+  else if(overflow && (c == '\n' || c == '\r' || (c == ':' && comment_mode == false)))
+  {
+    overflow = false;
+    return;
+  }
+
+  int i = (unsigned int)(rx_buffer.head + 1) % RX_BUFFER_SIZE;
+
+  // if we should be storing the received character into the location
+  // just before the tail (meaning that the head would advance to the
+  // current location of the tail), we're about to overflow the buffer
+  // and so we need to move the head back to the end of the previous line.
+  if (i != rx_buffer.tail) {
+    rx_buffer.buffer[rx_buffer.head] = c;
+    rx_buffer.head = i;
+  }
+  else {
+    overflow = true;
+    i = (uint8_t)(rx_buffer.head - 1) % RX_BUFFER_SIZE;
+    for(; !(rx_buffer.buffer[i] == '\n' ||
+            rx_buffer.buffer[i] == '\r' ||
+            (rx_buffer.buffer[i] == ':' && comment_mode != true)) &&
+            rx_buffer.head != rx_buffer.tail; rx_buffer.head = i)
+      i = (uint8_t)(rx_buffer.head - 1) % RX_BUFFER_SIZE;
+    rx_buffer.head = (uint8_t)(i + 1) % RX_BUFFER_SIZE;;
+    if(!rxbuf_filled)
+      rxbuf_filled = true;
+  }
 }
 
 
diff --git a/Marlin/Marlin_main.cpp b/Marlin/Marlin_main.cpp
index edc36914c3f5..ca27a6bbee4e 100644
--- a/Marlin/Marlin_main.cpp
+++ b/Marlin/Marlin_main.cpp
@@ -437,6 +437,7 @@ static bool send_ok[BUFSIZE];
 #endif
 
 #if ENABLED(HOST_KEEPALIVE_FEATURE)
+boolean comment_mode = false;
 
   // States for managing Marlin and host communication
   // Marlin sends messages if blocked or busy
@@ -967,6 +968,7 @@ void get_command() {
 
       // Add the command to the queue
       _enqueuecommand(serial_line_buffer, true);
+      rxbuf_filled = false;
     }
     else if (serial_count >= MAX_CMD_SIZE - 1) {
       // Keep fetching, but ignore normal characters beyond the max length
@@ -7165,6 +7167,16 @@ void plan_arc(
     */
   }
 
+  static bool reportrx_once = true;
+  if(rxbuf_filled && reportrx_once)
+  {
+    SERIAL_ERROR_START;
+    SERIAL_ERRORPGM(MSG_ERR_RXBUF_FULL);
+    reportrx_once = false;
+  }
+  else if(!rxbuf_filled)
+   reportrx_once = true;
+
 #endif // SCARA
 
 #if ENABLED(TEMP_STAT_LEDS)
diff --git a/Marlin/language.h b/Marlin/language.h
index 1b82ec314c83..ae4b5306f209 100644
--- a/Marlin/language.h
+++ b/Marlin/language.h
@@ -137,6 +137,7 @@
 #define MSG_ERR_CHECKSUM_MISMATCH           "checksum mismatch, Last Line: "
 #define MSG_ERR_NO_CHECKSUM                 "No Checksum with line number, Last Line: "
 #define MSG_ERR_NO_LINENUMBER_WITH_CHECKSUM "No Line Number with checksum, Last Line: "
+#define MSG_ERR_RXBUF_FULL                  "RXbuf full"
 #define MSG_FILE_PRINTED                    "Done printing file"
 #define MSG_BEGIN_FILE_LIST                 "Begin file list"
 #define MSG_END_FILE_LIST                   "End file list"