From 117da602ca1de742a61221790646da6241adf6b0 Mon Sep 17 00:00:00 2001
From: Lior Halphon <LIJI32@gmail.com>
Date: Sat, 23 Nov 2024 13:54:50 +0200
Subject: [PATCH] Prevent the rewind buffer from being reset unexpectedly on
 iOS

---
 iOS/GBViewController.m | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/iOS/GBViewController.m b/iOS/GBViewController.m
index 530589ad0..c760156ca 100644
--- a/iOS/GBViewController.m
+++ b/iOS/GBViewController.m
@@ -78,6 +78,9 @@ @implementation GBViewController
     UIButton *_printerButton;
     UIActivityIndicatorView *_printerSpinner;
     NSMutableData *_currentPrinterImageData;
+    
+    NSString *_lastSavedROM;
+    NSDate *_saveDate;
 }
 
 static void loadBootROM(GB_gameboy_t *gb, GB_boot_rom_t type)
@@ -697,7 +700,17 @@ - (void)loadROM
                     }
                 }
             }
-            GB_rewind_reset(&_gb);
+            
+            NSDate *date = nil;
+            [[NSURL fileURLWithPath:[GBROMManager sharedManager].autosaveStateFile] getResourceValue:&date
+                                                                                              forKey:NSURLContentModificationDateKey
+                                                                                               error:nil];
+            
+            // Reset the rewind buffer only if we switched ROMs or had the save state change externally
+            if (![_lastSavedROM isEqual:[GBROMManager sharedManager].currentROM] ||
+                ![_saveDate isEqual:date]) {
+                GB_rewind_reset(&_gb);
+            }
         }
     }
     else {
@@ -1155,6 +1168,14 @@ - (void)postRun
     if (!_swappingROM) {
         GB_save_battery(&_gb, [GBROMManager sharedManager].batterySaveFile.fileSystemRepresentation);
         [self saveStateToFile:[GBROMManager sharedManager].autosaveStateFile];
+
+        NSDate *date;
+        [[NSURL fileURLWithPath:[GBROMManager sharedManager].autosaveStateFile] getResourceValue:&date
+                                                                                          forKey:NSURLContentModificationDateKey
+                                                                                           error:nil];
+        _saveDate = date;
+        _lastSavedROM = [GBROMManager sharedManager].currentROM;
+
     }
     [[GBHapticManager sharedManager] setRumbleStrength:0];
     if (@available(iOS 14.0, *)) {