From e61e2d910e248da70735c4554a27c069e0ea4b32 Mon Sep 17 00:00:00 2001
From: Colin Cornaby <colin.cornaby@mac.com>
Date: Sun, 4 Feb 2024 15:40:46 -0800
Subject: [PATCH] Handling self patch copy errors

---
 .../Apps/plClient/Mac-Cocoa/PLSPatcher.h      |  2 +-
 .../Apps/plClient/Mac-Cocoa/PLSPatcher.mm     | 29 ++++++++++++++-----
 .../Plasma/Apps/plClient/Mac-Cocoa/main.mm    | 14 ++++++++-
 3 files changed, 36 insertions(+), 9 deletions(-)

diff --git a/Sources/Plasma/Apps/plClient/Mac-Cocoa/PLSPatcher.h b/Sources/Plasma/Apps/plClient/Mac-Cocoa/PLSPatcher.h
index fb6c956512..6e18ecffa2 100644
--- a/Sources/Plasma/Apps/plClient/Mac-Cocoa/PLSPatcher.h
+++ b/Sources/Plasma/Apps/plClient/Mac-Cocoa/PLSPatcher.h
@@ -60,7 +60,7 @@ NS_ASSUME_NONNULL_BEGIN
 @property(weak) id<PLSPatcherDelegate> delegate;
 @property(readonly) BOOL selfPatched;
 
-- (NSURL*)completeSelfPatch;
+- (NSURL*)completeSelfPatch:(NSError **)error;
 - (void)start;
 
 @end
diff --git a/Sources/Plasma/Apps/plClient/Mac-Cocoa/PLSPatcher.mm b/Sources/Plasma/Apps/plClient/Mac-Cocoa/PLSPatcher.mm
index ac506f1145..2138b7b5d5 100644
--- a/Sources/Plasma/Apps/plClient/Mac-Cocoa/PLSPatcher.mm
+++ b/Sources/Plasma/Apps/plClient/Mac-Cocoa/PLSPatcher.mm
@@ -114,21 +114,36 @@ - (void)start
     self.patcher->Start();
 }
 
-- (NSURL *)completeSelfPatch
+- (NSURL *)completeSelfPatch:(NSError **)error;
 {
     NSString* destinationPath = [NSString stringWithSTString:plManifest::PatcherExecutable().AsString()];
     NSURL* destinationURL = [NSURL fileURLWithPath:[NSString stringWithSTString:plManifest::PatcherExecutable().AsString()]];
     
+    NSError* errorInScope;
+    
     if ([NSFileManager.defaultManager fileExistsAtPath:destinationPath]) {
         // need to swap
-        renamex_np(destinationURL.path.fileSystemRepresentation, self.updatedClientURL.path.fileSystemRepresentation, RENAME_SWAP);
-        
-        // delete the old version - this is very likely us
-        // we want to terminate after. Our bundle will no longer be valid.
-        [NSFileManager.defaultManager removeItemAtURL:self.updatedClientURL error:nil];
+        int swapError = renamex_np(destinationURL.path.fileSystemRepresentation, self.updatedClientURL.path.fileSystemRepresentation, RENAME_SWAP);
+        if (swapError == 0) {
+            // delete the old version - this is very likely us
+            // we want to terminate after. Our bundle will no longer be valid.
+            [NSFileManager.defaultManager removeItemAtURL:self.updatedClientURL error:&errorInScope];
+        } else {
+            // abort and return an error
+            errorInScope = [NSError errorWithDomain:NSPOSIXErrorDomain code:swapError userInfo:nil];
+        }
     } else {
         // no executable already present! Just move things into place.
-        [NSFileManager.defaultManager moveItemAtURL:self.updatedClientURL toURL:destinationURL error:nil];
+        [NSFileManager.defaultManager moveItemAtURL:self.updatedClientURL toURL:destinationURL error:&errorInScope];
+    }
+    
+    if (errorInScope) {
+        // Try to clean up if there was an error
+        [NSFileManager.defaultManager removeItemAtURL:self.updatedClientURL error:nil];
+        if (error) {
+            *error = errorInScope;
+        }
+        return nil;
     }
     
     return destinationURL;
diff --git a/Sources/Plasma/Apps/plClient/Mac-Cocoa/main.mm b/Sources/Plasma/Apps/plClient/Mac-Cocoa/main.mm
index 37fc214ebb..bdac9f5115 100644
--- a/Sources/Plasma/Apps/plClient/Mac-Cocoa/main.mm
+++ b/Sources/Plasma/Apps/plClient/Mac-Cocoa/main.mm
@@ -427,7 +427,19 @@ - (void)patcherCompleted:(PLSPatcher *)patcher didSelfPatch:(BOOL)selfPatched
     [NSApp endModalSession:self.currentModalSession];
     [self.patcherWindow.window close];
     if (selfPatched) {
-        NSURL* finalURL = [patcher completeSelfPatch];
+        NSError *error;
+        NSURL* finalURL = [patcher completeSelfPatch:&error];
+        
+        if (error) {
+            // uh oh, we couldn't self patch, present the error and bail
+            // this should be very rare and could be related to permissions issues
+            // we expect the game directory to be writable by all
+            NSAlert *errorAlert = [NSAlert alertWithError:error];
+            [errorAlert runModal];
+            [NSApp terminate:self];
+            // return just in case we ever reach here
+            return;
+        }
         
         // Pass the "we've already patched" argument
         NSArray* applicationArguments = [[[NSProcessInfo processInfo] arguments] arrayByAddingObject:@"-NoSelfPatch"];