From 41c16006a1929d64e0e80ffcc7c323cef66a859d Mon Sep 17 00:00:00 2001
From: Stefan Kalscheuer <stefan@stklcode.de>
Date: Wed, 21 Dec 2022 16:48:58 +0100
Subject: [PATCH] fill the output buffer with blanks on DGUS2 clone displays

The intention behind the original logic was to fill the entire line with
blanks, so that the output buffer of the display gets "flushed". Restore
this behavior.
---
 Marlin/src/lcd/anycubic_touchscreen.cpp | 36 +++++++++++++++----------
 1 file changed, 22 insertions(+), 14 deletions(-)

diff --git a/Marlin/src/lcd/anycubic_touchscreen.cpp b/Marlin/src/lcd/anycubic_touchscreen.cpp
index db431353..48aac6bb 100755
--- a/Marlin/src/lcd/anycubic_touchscreen.cpp
+++ b/Marlin/src/lcd/anycubic_touchscreen.cpp
@@ -1193,10 +1193,10 @@
             // The longname may not be filed, so we use the built-in fallback here.
             char* fileName      = card.longest_filename();
             int fileNameLen     = strlen(fileName);
-            bool fileNameWasCut = false;
 
             // Cut off too long filenames. They don't fit on the screen anyway.
             #if ENABLED(KNUTWURST_DGUS2_TFT)
+              bool fileNameWasCut = false;
               if (fileNameLen > MAX_PRINTABLE_FILENAME_LEN) {
                 fileNameWasCut = true;
                 fileNameLen    = MAX_PRINTABLE_FILENAME_LEN;
@@ -1213,19 +1213,27 @@
                 outputString[i] = '_';
             }
 
-            // Terminate the string.
-            outputString[fileNameLen] = '\0';
-
-            // Append extension, if filename was truncated. I know, it's ugly, but it's faster than a string lib.
-            if (fileNameWasCut) {
-              outputString[fileNameLen - 7] = '~';
-              outputString[fileNameLen - 6] = '.';
-              outputString[fileNameLen - 5] = 'g';
-              outputString[fileNameLen - 4] = 'c';
-              outputString[fileNameLen - 3] = 'o';
-              outputString[fileNameLen - 2] = 'd';
-              outputString[fileNameLen - 1] = 'e';
-            }
+            #if ENABLED(KNUTWURST_DGUS2_TFT)
+              // Append extension, if filename was truncated. I know, it's ugly, but it's faster than a string lib.
+              if (fileNameWasCut) {
+                outputString[fileNameLen - 7] = '~';
+                outputString[fileNameLen - 6] = '.';
+                outputString[fileNameLen - 5] = 'g';
+                outputString[fileNameLen - 4] = 'c';
+                outputString[fileNameLen - 3] = 'o';
+                outputString[fileNameLen - 2] = 'd';
+                outputString[fileNameLen - 1] = 'e';
+              } else {
+                // Make sure to fill the output buffer with blanks.
+                for (unsigned char i = fileNameLen; i < MAX_PRINTABLE_FILENAME_LEN; i++) {
+                  outputString[i] = ' ';
+                }
+              }
+              outputString[MAX_PRINTABLE_FILENAME_LEN] = '\0';
+            #else
+              // Just terminate the string.
+              outputString[fileNameLen] = '\0';
+            #endif
 
             if (card.flag.filenameIsDir) {
               #if ENABLED(KNUTWURST_DGUS2_TFT)