From 9262475cb47c1bbfd4422591394b789ce18f6b6b Mon Sep 17 00:00:00 2001
From: Vicki Pfau <vi@endrift.com>
Date: Fri, 9 Nov 2018 20:31:30 -0800
Subject: [PATCH] GBA Savedata: Fix various filesize edge cases (fixes #1221)

---
 src/gba/savedata.c               | 20 +++++++++-----------
 src/platform/libretro/libretro.c |  1 +
 2 files changed, 10 insertions(+), 11 deletions(-)

diff --git a/src/gba/savedata.c b/src/gba/savedata.c
index 8cf291f24..10f9499fa 100644
--- a/src/gba/savedata.c
+++ b/src/gba/savedata.c
@@ -259,9 +259,6 @@ void GBASavedataInitFlash(struct GBASavedata* savedata) {
 		end = savedata->vf->size(savedata->vf);
 		if (end < flashSize) {
 			savedata->vf->truncate(savedata->vf, flashSize);
-		} else if (end >= SIZE_CART_FLASH1M) {
-			flashSize = SIZE_CART_FLASH1M;
-			savedata->type = SAVEDATA_FLASH1M;
 		}
 		savedata->data = savedata->vf->map(savedata->vf, flashSize, savedata->mapMode);
 	}
@@ -291,9 +288,6 @@ void GBASavedataInitEEPROM(struct GBASavedata* savedata) {
 		end = savedata->vf->size(savedata->vf);
 		if (end < eepromSize) {
 			savedata->vf->truncate(savedata->vf, eepromSize);
-		} else if (end >= SIZE_CART_EEPROM) {
-			eepromSize = SIZE_CART_EEPROM;
-			savedata->type = SAVEDATA_EEPROM;
 		}
 		savedata->data = savedata->vf->map(savedata->vf, eepromSize, savedata->mapMode);
 	}
@@ -439,13 +433,17 @@ static void _ensureEeprom(struct GBASavedata* savedata, uint32_t size) {
 		return;
 	}
 	savedata->type = SAVEDATA_EEPROM;
-	if (!savedata->vf || savedata->vf->size(savedata->vf) > SIZE_CART_EEPROM512) {
+	if (!savedata->vf) {
 		return;
 	}
 	savedata->vf->unmap(savedata->vf, savedata->data, SIZE_CART_EEPROM512);
-	savedata->vf->truncate(savedata->vf, SIZE_CART_EEPROM);
-	savedata->data = savedata->vf->map(savedata->vf, SIZE_CART_EEPROM, savedata->mapMode);
-	memset(&savedata->data[SIZE_CART_EEPROM512], 0xFF, SIZE_CART_EEPROM - SIZE_CART_EEPROM512);
+	if (savedata->vf->size(savedata->vf) < SIZE_CART_EEPROM) {
+		savedata->vf->truncate(savedata->vf, SIZE_CART_EEPROM);
+		savedata->data = savedata->vf->map(savedata->vf, SIZE_CART_EEPROM, savedata->mapMode);
+		memset(&savedata->data[SIZE_CART_EEPROM512], 0xFF, SIZE_CART_EEPROM - SIZE_CART_EEPROM512);
+	} else {
+		savedata->data = savedata->vf->map(savedata->vf, SIZE_CART_EEPROM, savedata->mapMode);
+	}
 }
 
 void GBASavedataWriteEEPROM(struct GBASavedata* savedata, uint16_t value, uint32_t writeSize) {
@@ -605,7 +603,7 @@ void _flashSwitchBank(struct GBASavedata* savedata, int bank) {
 		savedata->type = SAVEDATA_FLASH1M;
 		if (savedata->vf) {
 			savedata->vf->unmap(savedata->vf, savedata->data, SIZE_CART_FLASH512);
-			if (savedata->vf->size(savedata->vf) == SIZE_CART_FLASH512) {
+			if (savedata->vf->size(savedata->vf) < SIZE_CART_FLASH1M) {
 				savedata->vf->truncate(savedata->vf, SIZE_CART_FLASH1M);
 				savedata->data = savedata->vf->map(savedata->vf, SIZE_CART_FLASH1M, MAP_WRITE);
 				memset(&savedata->data[SIZE_CART_FLASH512], 0xFF, SIZE_CART_FLASH512);
diff --git a/src/platform/libretro/libretro.c b/src/platform/libretro/libretro.c
index 06a9638b1..57bd74296 100644
--- a/src/platform/libretro/libretro.c
+++ b/src/platform/libretro/libretro.c
@@ -489,6 +489,7 @@ bool retro_load_game(const struct retro_game_info* game) {
 	core->setPeripheral(core, mPERIPH_RUMBLE, &rumble);
 
 	savedata = anonymousMemoryMap(SIZE_CART_FLASH1M);
+	memset(savedata, 0xFF, SIZE_CART_FLASH1M);
 	struct VFile* save = VFileFromMemory(savedata, SIZE_CART_FLASH1M);
 
 	_reloadSettings();