file_sys: handle null romfs

src/core/file_sys/patch_manager.cpp

@@ -429,10 +429,6 @@ VirtualFile PatchManager::PatchRomFS(const NCA* base_nca, VirtualFile base_romfs
         LOG_DEBUG(Loader, "{}", log_string);
     }
 
-    if (base_romfs == nullptr) {
-        return base_romfs;
-    }
-
     auto romfs = base_romfs;
 
     // Game Updates

src/core/file_sys/romfs.cpp

@@ -3,6 +3,7 @@
 
 #include <memory>
 
+#include "common/assert.h"
 #include "common/common_types.h"
 #include "common/string_util.h"
 #include "common/swap.h"
@@ -101,24 +102,30 @@ void ProcessDirectory(const VirtualFile& file, std::size_t dir_offset, std::size
 } // Anonymous namespace
 
 VirtualDir ExtractRomFS(VirtualFile file) {
-    RomFSHeader header{};
-    if (file->ReadObject(&header) != sizeof(RomFSHeader))
-        return nullptr;
+    auto root_container = std::make_shared<VectorVfsDirectory>();
+    if (!file) {
+        return root_container;
+    }
 
-    if (header.header_size != sizeof(RomFSHeader))
-        return nullptr;
+    RomFSHeader header{};
+    if (file->ReadObject(&header) != sizeof(RomFSHeader)) {
+        return root_container;
+    }
+
+    if (header.header_size != sizeof(RomFSHeader)) {
+        return root_container;
+    }
 
     const u64 file_offset = header.file_meta.offset;
     const u64 dir_offset = header.directory_meta.offset;
 
-    auto root_container = std::make_shared<VectorVfsDirectory>();
-
     ProcessDirectory(file, dir_offset, file_offset, header.data_offset, 0, root_container);
 
     if (auto root = root_container->GetSubdirectory(""); root) {
         return std::make_shared<CachedVfsDirectory>(std::move(root));
     }
 
+    ASSERT(false);
     return nullptr;
 }
 

src/core/file_sys/romfs_factory.cpp

@@ -22,7 +22,7 @@ RomFSFactory::RomFSFactory(Loader::AppLoader& app_loader, ContentProvider& provi
     : content_provider{provider}, filesystem_controller{controller} {
     // Load the RomFS from the app
     if (app_loader.ReadRomFS(file) != Loader::ResultStatus::Success) {
-        LOG_ERROR(Service_FS, "Unable to read RomFS!");
+        LOG_WARNING(Service_FS, "Unable to read base RomFS");
     }
 
     updatable = app_loader.IsRomFSUpdatable();

src/core/loader/nca.cpp

@@ -74,10 +74,8 @@ AppLoader_NCA::LoadResult AppLoader_NCA::Load(Kernel::KProcess& process, Core::S
         return load_result;
     }
 
-    if (nca->GetRomFS() != nullptr && nca->GetRomFS()->GetSize() > 0) {
     system.GetFileSystemController().RegisterRomFS(std::make_unique<FileSys::RomFSFactory>(
         *this, system.GetContentProvider(), system.GetFileSystemController()));
-    }
 
     is_loaded = true;
     return load_result;

src/yuzu/main.cpp

@@ -2713,11 +2713,6 @@ void GMainWindow::OnGameListDumpRomFS(u64 program_id, const std::string& game_pa
     }
 
     const auto base_romfs = base_nca->GetRomFS();
-    if (!base_romfs) {
-        failed();
-        return;
-    }
-
     const auto dump_dir =
         target == DumpRomFSTarget::Normal
             ? Common::FS::GetYuzuPath(Common::FS::YuzuPath::DumpDir)