Address review feedback on save state implementation

- Zero-fill remaining bytes in retro_serialize() for deterministic
  save states and add bounds check against STATE_SIZE overflow
- Include eeprom_ram[64] and cdromEEPROM[64] in EepromStateSave/Load
  so EEPROM contents are preserved across save/load cycles
- Include audioEnabled and joysticksEnabled flags in JoystickStateSave/Load
  so derived state from joystick_ram writes is not stale after load

Co-Authored-By: Claude Opus 4.6 <[email protected]>

Author: JoeMatt

libretro.c

@@ -782,13 +782,15 @@ size_t retro_serialize_size(void)
 
 bool retro_serialize(void *data, size_t size)
 {
-   uint8_t *buf;
+   uint8_t *buf, *start;
+   size_t written;
    uint32_t magic, version, flags, reserved;
 
    if (!data || size < STATE_SIZE)
       return false;
 
-   buf = (uint8_t *)data;
+   start = (uint8_t *)data;
+   buf   = start;
 
    /* Header */
    magic    = STATE_MAGIC;
@@ -825,6 +827,14 @@ bool retro_serialize(void *data, size_t size)
    buf += MTStateSave(buf);
    buf += DACStateSave(buf);
 
+   written = (size_t)(buf - start);
+   if (written > STATE_SIZE)
+      return false;
+
+   /* Zero-fill remaining bytes for deterministic save states */
+   if (written < STATE_SIZE)
+      memset(buf, 0, STATE_SIZE - written);
+
    return true;
 }
 

src/eeprom.c

@@ -451,6 +451,10 @@ size_t EepromStateSave(uint8_t *buf)
 	STATE_SAVE_VAR(buf, jerry_writes_enabled);
 	STATE_SAVE_VAR(buf, jerry_ee_direct_jump);
 
+	/* EEPROM data arrays */
+	STATE_SAVE_BUF(buf, eeprom_ram, sizeof(eeprom_ram));
+	STATE_SAVE_BUF(buf, cdromEEPROM, sizeof(cdromEEPROM));
+
 	return (size_t)(buf - start);
 }
 
@@ -468,6 +472,10 @@ size_t EepromStateLoad(const uint8_t *buf)
 	STATE_LOAD_VAR(buf, jerry_writes_enabled);
 	STATE_LOAD_VAR(buf, jerry_ee_direct_jump);
 
+	/* EEPROM data arrays */
+	STATE_LOAD_BUF(buf, eeprom_ram, sizeof(eeprom_ram));
+	STATE_LOAD_BUF(buf, cdromEEPROM, sizeof(cdromEEPROM));
+
 	return (size_t)(buf - start);
 }
 

src/joystick.c

@@ -161,6 +161,8 @@ size_t JoystickStateSave(uint8_t *buf)
 	STATE_SAVE_BUF(buf, joystick_ram, sizeof(joystick_ram));
 	STATE_SAVE_BUF(buf, joypad0Buttons, sizeof(joypad0Buttons));
 	STATE_SAVE_BUF(buf, joypad1Buttons, sizeof(joypad1Buttons));
+	STATE_SAVE_VAR(buf, audioEnabled);
+	STATE_SAVE_VAR(buf, joysticksEnabled);
 
 	return (size_t)(buf - start);
 }
@@ -172,6 +174,8 @@ size_t JoystickStateLoad(const uint8_t *buf)
 	STATE_LOAD_BUF(buf, joystick_ram, sizeof(joystick_ram));
 	STATE_LOAD_BUF(buf, joypad0Buttons, sizeof(joypad0Buttons));
 	STATE_LOAD_BUF(buf, joypad1Buttons, sizeof(joypad1Buttons));
+	STATE_LOAD_VAR(buf, audioEnabled);
+	STATE_LOAD_VAR(buf, joysticksEnabled);
 
 	return (size_t)(buf - start);
 }