Fix auto#.g file handling, add NO_SD_AUTOSTART (#20071)

Marlin/Configuration_adv.h

 
   #define SD_MENU_CONFIRM_START             // Confirm the selected SD file before printing
 
+  //#define NO_SD_AUTOSTART                 // Remove auto#.g file support completely to save some Flash, SRAM
   //#define MENU_ADDAUTOSTART               // Add a menu option to run auto#.g files
 
   //#define BROWSE_MEDIA_ON_INSERT          // Open the file browser when media is inserted

Marlin/src/MarlinCore.cpp

 #if ENABLED(SDSUPPORT)
 
   inline void abortSDPrinting() {
+    IF_DISABLED(NO_SD_AUTOSTART, card.autofile_cancel());
     card.endFilePrint(TERN_(SD_RESORT, true));
     queue.clear();
     quickstop_stepper();
       if (ELAPSED(ms, next_home_key_ms)) {
         next_home_key_ms = ms + HOME_DEBOUNCE_DELAY;
         LCD_MESSAGEPGM(MSG_AUTO_HOME);
-        queue.enqueue_now_P(G28_STR);
+        queue.inject_P(G28_STR);
       }
     }
   #endif
     idle();
 
     #if ENABLED(SDSUPPORT)
-      card.checkautostart();
       if (card.flag.abort_sd_printing) abortSDPrinting();
       if (marlin_state == MF_SD_COMPLETE) finishSDPrinting();
     #endif

Marlin/src/feature/powerloss.h

     static void resume();
     static void purge();
 
-    static inline void cancel() { purge(); card.autostart_index = 0; }
+    static inline void cancel() { purge(); IF_DISABLED(NO_SD_AUTOSTART, card.autofile_begin()); }
 
     static void load();
     static void save(const bool force=ENABLED(SAVE_EACH_CMD_MODE), const float zraise=0);

Marlin/src/gcode/sd/M1001.cpp

 #include "../gcode.h"
 #include "../../module/printcounter.h"
 
+#if DISABLED(NO_SD_AUTOSTART)
+  #include "../../sd/cardreader.h"
+#endif
+
 #ifdef SD_FINISHED_RELEASECOMMAND
   #include "../queue.h"
 #endif
  * M1001: Execute actions for SD print completion
  */
 void GcodeSuite::M1001() {
+  // If there's another auto#.g file to run...
+  if (TERN(NO_SD_AUTOSTART, false, card.autofile_check())) return;
+
+  // Purge the recovery file...
+  TERN_(POWER_LOSS_RECOVERY, recovery.purge());
 
   // Report total print time
   const bool long_print = print_job_timer.duration() > 60;
   // Set the progress bar "done" state
   TERN_(LCD_SET_PROGRESS_MANUALLY, ui.set_progress_done());
 
-  // Purge the recovery file
-  TERN_(POWER_LOSS_RECOVERY, recovery.purge());
-
   // Announce SD file completion
   {
     PORT_REDIRECT(SERIAL_BOTH);
 
   // Inject SD_FINISHED_RELEASECOMMAND, if any
   #ifdef SD_FINISHED_RELEASECOMMAND
-    queue.inject_P(PSTR(SD_FINISHED_RELEASECOMMAND));
+    gcode.process_subcommands_now_P(PSTR(SD_FINISHED_RELEASECOMMAND));
   #endif
 
   TERN_(EXTENSIBLE_UI, ExtUI::onPrintFinished());

Marlin/src/inc/Conditionals_adv.h

   #undef SD_FINISHED_RELEASECOMMAND
 #endif
 
+#if ENABLED(NO_SD_AUTOSTART)
+  #undef MENU_ADDAUTOSTART
+#endif
+
 #if EITHER(SDSUPPORT, LCD_SET_PROGRESS_MANUALLY)
   #define HAS_PRINT_PROGRESS 1
 #endif

Marlin/src/lcd/menu/menu_main.cpp

       // Run Auto Files
       //
       #if ENABLED(MENU_ADDAUTOSTART)
-        ACTION_ITEM(MSG_RUN_AUTO_FILES, card.beginautostart);
+        ACTION_ITEM(MSG_RUN_AUTO_FILES, card.autofile_begin);
       #endif
 
       if (card_detected) {
       // Autostart
       //
       #if ENABLED(MENU_ADDAUTOSTART)
-        ACTION_ITEM(MSG_RUN_AUTO_FILES, card.beginautostart);
+        ACTION_ITEM(MSG_RUN_AUTO_FILES, card.autofile_begin);
       #endif
 
       if (card_detected) {

Marlin/src/sd/cardreader.cpp

 
 card_flags_t CardReader::flag;
 char CardReader::filename[FILENAME_LENGTH], CardReader::longFilename[LONG_FILENAME_LENGTH];
-int8_t CardReader::autostart_index;
+
+IF_DISABLED(NO_SD_AUTOSTART, uint8_t CardReader::autofile_index); // = 0
 
 #if BOTH(HAS_MULTI_SERIAL, BINARY_FILE_TRANSFER)
   int8_t CardReader::transfer_port_index;
       //sort_reverse = false;
     #endif
   #endif
+
   flag.sdprinting = flag.mounted = flag.saving = flag.logging = false;
   filesize = sdpos = 0;
 
   TERN_(HAS_MEDIA_SUBCALLS, file_subcall_ctr = 0);
 
+  IF_DISABLED(NO_SD_AUTOSTART, autofile_cancel());
+
   workDirDepth = 0;
   ZERO(workDirParents);
 
-  // Disable autostart until card is initialized
-  autostart_index = -1;
-
   #if ENABLED(SDSUPPORT) && PIN_EXISTS(SD_DETECT)
     SET_INPUT_PULLUP(SD_DETECT_PIN);
   #endif
 
     if (stat) {
       TERN_(SDCARD_EEPROM_EMULATION, settings.first_load());
-      if (old_stat == 2)              // First mount?
+      if (old_stat == 2) {            // First mount?
         DEBUG_ECHOLNPGM("First mount.");
-        TERN(POWER_LOSS_RECOVERY,
-          recovery.check(),           // Check for PLR file. (If not there it will beginautostart)
-          beginautostart()            // Look for auto0.g on the next loop
-        );
+        #if ENABLED(POWER_LOSS_RECOVERY)
+          recovery.check();           // Check for PLR file. (If not there then call autofile_begin)
+        #elif DISABLED(NO_SD_AUTOSTART)
+          autofile_begin();           // Look for auto0.g on the next loop
+        #endif
+      }
     }
   }
   else
  * Enqueues M23 and M24 commands to initiate a media print.
  */
 void CardReader::openAndPrintFile(const char *name) {
-  char cmd[4 + strlen(name) + 1]; // Room for "M23 ", filename, and null
+  char cmd[4 + strlen(name) + 1 + 3 + 1]; // Room for "M23 ", filename, "\n", "M24", and null
   extern const char M23_STR[];
   sprintf_P(cmd, M23_STR, name);
   for (char *c = &cmd[4]; *c; c++) *c = tolower(*c);
-  queue.enqueue_one_now(cmd);
-  queue.enqueue_now_P(M24_STR);
+  strcat_P(cmd, PSTR("\nM24"));
+  queue.inject(cmd);
 }
 
 /**
 
 void CardReader::openLogFile(char * const path) {
   flag.logging = DISABLED(SDCARD_READONLY);
-  TERN(SDCARD_READONLY,,openFileWrite(path));
+  IF_DISABLED(SDCARD_READONLY, openFileWrite(path));
 }
 
 //
   if (file.writeError) SERIAL_ERROR_MSG(STR_SD_ERR_WRITE_TO_FILE);
 }
 
-//
-// Run the next autostart file. Called:
-// - On boot after successful card init
-// - After finishing the previous autostart file
-// - From the LCD command to run the autostart file
-//
-
-void CardReader::checkautostart() {
-
-  if (autostart_index < 0 || flag.sdprinting) return;
-
-  if (!isMounted()) mount();
-  TERN_(SDCARD_EEPROM_EMULATION, else settings.first_load());
+#if DISABLED(NO_SD_AUTOSTART)
+  /**
+   * Run all the auto#.g files. Called:
+   * - On boot after successful card init.
+   * - From the LCD command to Run Auto Files
+   */
+  void CardReader::autofile_begin() {
+    autofile_index = 1;
+    (void)autofile_check();
+  }
 
-  // Don't run auto#.g when a PLR file exists
-  if (isMounted() && TERN1(POWER_LOSS_RECOVERY, !recovery.valid())) {
-    char autoname[8];
-    sprintf_P(autoname, PSTR("auto%c.g"), autostart_index + '0');
-    dir_t p;
-    root.rewind();
-    while (root.readDir(&p, nullptr) > 0) {
-      for (int8_t i = (int8_t)strlen((char*)p.name); i--;) p.name[i] = tolower(p.name[i]);
-      if (p.name[9] != '~' && strncmp((char*)p.name, autoname, 5) == 0) {
+  /**
+   * Run the next auto#.g file. Called:
+   *   - On boot after successful card init
+   *   - After finishing the previous auto#.g file
+   *   - From the LCD command to begin the auto#.g files
+   *
+   * Return 'true' if there was nothing to do
+   */
+  bool CardReader::autofile_check() {
+    if (!autofile_index) return true;
+
+    if (!isMounted())
+      mount();
+    else if (ENABLED(SDCARD_EEPROM_EMULATION))
+      settings.first_load();
+
+    // Don't run auto#.g when a PLR file exists
+    if (isMounted() && TERN1(POWER_LOSS_RECOVERY, !recovery.valid())) {
+      char autoname[10];
+      sprintf_P(autoname, PSTR("/auto%c.g"), '0' + autofile_index - 1);
+      if (fileExists(autoname)) {
+        cdroot();
         openAndPrintFile(autoname);
-        autostart_index++;
-        return;
+        autofile_index++;
+        return false;
       }
     }
+    autofile_cancel();
+    return true;
   }
-  autostart_index = -1;
-}
-
-void CardReader::beginautostart() {
-  autostart_index = 0;
-  cdroot();
-}
+#endif
 
 void CardReader::closefile(const bool store_location/*=false*/) {
   file.sync();

Marlin/src/sd/cardreader.h

   static void openLogFile(char * const path);
   static void write_command(char * const buf);
 
-  // Auto-Start files
-  static int8_t autostart_index;                    // Index of autoX.g files
-  static void beginautostart();
-  static void checkautostart();
+  #if DISABLED(NO_SD_AUTOSTART)     // Auto-Start auto#.g file handling
+    static uint8_t autofile_index;  // Next auto#.g index to run, plus one. Ignored by autofile_check when zero.
+    static void autofile_begin();   // Begin check. Called automatically after boot-up.
+    static bool autofile_check();   // Check for the next auto-start file and run it.
+    static inline void autofile_cancel() { autofile_index = 0; }
+  #endif
 
   // Basic file ops
   static void openFileRead(char * const path, const uint8_t subcall=0);

buildroot/tests/mega2560-tests

 opt_set TEMP_SENSOR_BED 1
 opt_enable AUTO_BED_LEVELING_UBL RESTORE_LEVELING_AFTER_G28 DEBUG_LEVELING_FEATURE G26_MESH_VALIDATION ENABLE_LEVELING_FADE_HEIGHT SKEW_CORRECTION \
            REPRAP_DISCOUNT_FULL_GRAPHIC_SMART_CONTROLLER LIGHTWEIGHT_UI STATUS_MESSAGE_SCROLLING BOOT_MARLIN_LOGO_SMALL \
-           SDSUPPORT SDCARD_SORT_ALPHA USB_FLASH_DRIVE_SUPPORT SCROLL_LONG_FILENAMES CANCEL_OBJECTS \
+           SDSUPPORT SDCARD_SORT_ALPHA USB_FLASH_DRIVE_SUPPORT SCROLL_LONG_FILENAMES CANCEL_OBJECTS NO_SD_AUTOSTART \
            EEPROM_SETTINGS EEPROM_CHITCHAT GCODE_MACROS CUSTOM_USER_MENUS \
            MULTI_NOZZLE_DUPLICATION CLASSIC_JERK LIN_ADVANCE QUICK_HOME \
            LCD_SET_PROGRESS_MANUALLY PRINT_PROGRESS_SHOW_DECIMALS SHOW_REMAINING_TIME \