Updater: Preserve non-standard exe names on update

updater/Windows/WindowsUpdater.cpp

@@ -453,7 +453,7 @@ int WINAPI wWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPWSTR lpCmdLi
 	const int parent_process_id = StringUtil::FromChars<int>(StringUtil::WideStringToUTF8String(argv[1])).value_or(0);
 	const std::string destination_directory = StringUtil::WideStringToUTF8String(argv[2]);
 	const std::string zip_path = StringUtil::WideStringToUTF8String(argv[3]);
-	std::wstring program_to_launch(argv[4]);
+	const std::wstring program_to_launch(argv[4]);
 	argv.reset();
 
 	if (parent_process_id <= 0 || destination_directory.empty() || zip_path.empty() || program_to_launch.empty())
@@ -493,7 +493,6 @@ int WINAPI wWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPWSTR lpCmdLi
 		return 1;
 	}
 
-	DeleteFileW(program_to_launch.c_str()); // In case the new exe has a different name, delete the old one to prevent confusion
 	if (!updater.CommitUpdate())
 	{
 		progress.ModalError(
@@ -504,22 +503,26 @@ int WINAPI wWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPWSTR lpCmdLi
 	updater.CleanupStagingDirectory();
 	updater.RemoveUpdateZip();
 
-	progress.ModalInformation("Update complete.");
-
-	if (GetFileAttributesW(program_to_launch.c_str()) == INVALID_FILE_ATTRIBUTES)
+	// Rename the new executable to match the existing one
+	if (std::string actual_exe = updater.FindPCSX2Exe(); !actual_exe.empty())
 	{
-		// New executable doesn't match old, try to find the real one...
-		if (std::string actual_exe = updater.FindPCSX2Exe(); !actual_exe.empty())
+		const std::string full_path = destination_directory + FS_OSPATH_SEPARATOR_STR + actual_exe;
+		progress.DisplayFormattedInformation("Moving '%s' to '%S'", full_path.c_str(), program_to_launch.c_str());
+		const bool ok = MoveFileExW(StringUtil::UTF8StringToWideString(full_path).c_str(),
+			program_to_launch.c_str(), MOVEFILE_REPLACE_EXISTING);
+		if (!ok)
 		{
-			std::string full_path = destination_directory + FS_OSPATH_SEPARATOR_STR + actual_exe;
-			program_to_launch = StringUtil::UTF8StringToWideString(full_path);
-		}
-		else
-		{
-			progress.ModalError("Couldn't find PCSX2 in update package, please re-download a fresh version from GitHub.");
+			progress.DisplayFormattedModalError("Failed to rename '%s' to %S", full_path.c_str(), program_to_launch.c_str());
 			return 1;
 		}
 	}
+	else
+	{
+		progress.ModalError("Couldn't find PCSX2 in update package, please re-download a fresh version from GitHub.");
+		return 1;
+	}
+
+	progress.ModalInformation("Update complete.");
 
 	progress.DisplayFormattedInformation("Launching '%s'...",
 		StringUtil::WideStringToUTF8String(program_to_launch).c_str());