From 2d22902d080b08c65ebdf5f8b3f03529ccd58144 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Gina=20H=C3=A4u=C3=9Fge?= <osd@foosel.net>
Date: Thu, 24 Jul 2014 12:04:02 +0200
Subject: [PATCH] Fix for a wrong checksum truncation for certain commands

Positioning of string terminator to truncate checksum from the commands
M23, M28, M30, M32, M928 and M117 was off by one, causing the last
letter of the actual command to be truncated instead of just the
checksum.

In case of the SD commands this caused checksummed commands targeting
existing files to fail since the last letter of the filename was
truncated.

In case of M117 this caused the last given letter not to be displayed.

This patch fixes the off-by-one error and sets the null terminator
on the exact position of the * starting the checksum instead of the
character before that.
---
 Marlin/Marlin_main.cpp | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/Marlin/Marlin_main.cpp b/Marlin/Marlin_main.cpp
index c4afca7f68..c09585e5bb 100644
--- a/Marlin/Marlin_main.cpp
+++ b/Marlin/Marlin_main.cpp
@@ -1693,7 +1693,7 @@ void process_commands()
     case 23: //M23 - Select file
       starpos = (strchr(strchr_pointer + 4,'*'));
       if(starpos!=NULL)
-        *(starpos-1)='\0';
+        *(starpos)='\0';
       card.openFile(strchr_pointer + 4,true);
       break;
     case 24: //M24 - Start SD print
@@ -1716,7 +1716,7 @@ void process_commands()
       if(starpos != NULL){
         char* npos = strchr(cmdbuffer[bufindr], 'N');
         strchr_pointer = strchr(npos,' ') + 1;
-        *(starpos-1) = '\0';
+        *(starpos) = '\0';
       }
       card.openFile(strchr_pointer+4,false);
       break;
@@ -1731,7 +1731,7 @@ void process_commands()
         if(starpos != NULL){
           char* npos = strchr(cmdbuffer[bufindr], 'N');
           strchr_pointer = strchr(npos,' ') + 1;
-          *(starpos-1) = '\0';
+          *(starpos) = '\0';
         }
         card.removeFile(strchr_pointer + 4);
       }
@@ -1753,7 +1753,7 @@ void process_commands()
         namestartpos++; //to skip the '!'
 
       if(starpos!=NULL)
-        *(starpos-1)='\0';
+        *(starpos)='\0';
 
       bool call_procedure=(code_seen('P'));
 
@@ -1776,7 +1776,7 @@ void process_commands()
       if(starpos != NULL){
         char* npos = strchr(cmdbuffer[bufindr], 'N');
         strchr_pointer = strchr(npos,' ') + 1;
-        *(starpos-1) = '\0';
+        *(starpos) = '\0';
       }
       card.openLogFile(strchr_pointer+5);
       break;
@@ -2193,7 +2193,7 @@ void process_commands()
     case 117: // M117 display message
       starpos = (strchr(strchr_pointer + 5,'*'));
       if(starpos!=NULL)
-        *(starpos-1)='\0';
+        *(starpos)='\0';
       lcd_setstatus(strchr_pointer + 5);
       break;
     case 114: // M114