Reorder error handling in extdata FS::CreateFile (#7346)

* Reorder error handling in extdata CreateFile

* Apply suggestions

src/core/file_sys/archive_extsavedata.cpp

@@ -92,7 +92,7 @@ class ExtSaveDataArchive : public SaveDataArchive {
 public:
     explicit ExtSaveDataArchive(const std::string& mount_point,
                                 std::unique_ptr<DelayGenerator> delay_generator_)
-        : SaveDataArchive(mount_point) {
+        : SaveDataArchive(mount_point, false) {
         delay_generator = std::move(delay_generator_);
     }
 
@@ -155,14 +155,6 @@ public:
                                                  std::move(delay_generator));
     }
 
-    Result CreateFile(const Path& path, u64 size) const override {
-        if (size == 0) {
-            LOG_ERROR(Service_FS, "Zero-size file is not supported");
-            return ResultUnsupportedOpenFlags;
-        }
-        return SaveDataArchive::CreateFile(path, size);
-    }
-
 private:
     ExtSaveDataArchive() = default;
     template <class Archive>

src/core/file_sys/savedata_archive.cpp

@@ -232,8 +232,13 @@ Result SaveDataArchive::CreateFile(const FileSys::Path& path, u64 size) const {
     }
 
     if (size == 0) {
-        FileUtil::CreateEmptyFile(full_path);
-        return ResultSuccess;
+        if (allow_zero_size_create) {
+            FileUtil::CreateEmptyFile(full_path);
+            return ResultSuccess;
+        } else {
+            LOG_DEBUG(Service_FS, "Zero-size file is not supported");
+            return ResultUnsupportedOpenFlags;
+        }
     }
 
     FileUtil::IOFile file(full_path, "wb");

src/core/file_sys/savedata_archive.h

@@ -15,7 +15,8 @@ namespace FileSys {
 /// Archive backend for general save data archive type (SaveData and SystemSaveData)
 class SaveDataArchive : public ArchiveBackend {
 public:
-    explicit SaveDataArchive(const std::string& mount_point_) : mount_point(mount_point_) {}
+    explicit SaveDataArchive(const std::string& mount_point_, bool allow_zero_size_create_ = true)
+        : mount_point(mount_point_), allow_zero_size_create(allow_zero_size_create_) {}
 
     std::string GetName() const override {
         return "SaveDataArchive: " + mount_point;
@@ -35,6 +36,7 @@ public:
 
 protected:
     std::string mount_point;
+    bool allow_zero_size_create;
     SaveDataArchive() = default;
 
 private:
@@ -42,6 +44,7 @@ private:
     void serialize(Archive& ar, const unsigned int) {
         ar& boost::serialization::base_object<ArchiveBackend>(*this);
         ar& mount_point;
+        ar& allow_zero_size_create;
     }
     friend class boost::serialization::access;
 };