[VFS] Fixed allow_game_relative_writes to write invalid cached entries

This PR fixes https://github.com/xenia-canary/xenia-canary/issues/123 a bug where files would not write to the host if they were deleted from the host filesystem during runtime.

src/xenia/vfs/devices/host_path_entry.cc

@@ -103,9 +103,10 @@ bool HostPathEntry::DeleteEntryInternal(Entry* entry) {
     auto removed = std::filesystem::remove_all(full_path, ec);
     return removed >= 1 && removed != static_cast<std::uintmax_t>(-1);
   } else {
-    // Delete file.
+    // Delete file only if it exists.
     return !std::filesystem::is_directory(full_path) &&
-           std::filesystem::remove(full_path, ec);
+           (!std::filesystem::exists(full_path) ||
+            std::filesystem::remove(full_path, ec));
   }
 }
 

src/xenia/vfs/devices/host_path_entry.h

@@ -30,7 +30,7 @@ class HostPathEntry : public Entry {
                                const std::filesystem::path& full_path,
                                xe::filesystem::FileInfo file_info);
 
-  const std::filesystem::path& host_path() { return host_path_; }
+  const std::filesystem::path& host_path() const { return host_path_; }
 
   X_STATUS Open(uint32_t desired_access, File** out_file) override;
 

src/xenia/vfs/virtual_file_system.cc

@@ -11,6 +11,7 @@
 #include "xenia/kernel/xam/content_manager.h"
 #include "xenia/vfs/devices/stfs_container_device.h"
 
+#include "devices/host_path_entry.h"
 #include "xenia/base/literals.h"
 #include "xenia/base/logging.h"
 #include "xenia/base/string.h"
@@ -221,6 +222,22 @@ X_STATUS VirtualFileSystem::OpenFile(Entry* root_entry,
     if (entry->attributes() & kFileAttributeDirectory && is_non_directory) {
       return X_STATUS_FILE_IS_A_DIRECTORY;
     }
+
+    // If the entry does not exist on the host then remove the cached entry
+    if (parent_entry) {
+      const xe::vfs::HostPathEntry* host_Path =
+          dynamic_cast<const xe::vfs::HostPathEntry*>(parent_entry);
+
+      if (host_Path) {
+        auto const file_path = host_Path->host_path() / entry->name();
+
+        if (!std::filesystem::exists(file_path)) {
+          // Remove cached entry
+          entry->Delete();
+          entry = nullptr;
+        }
+      }
+    }
   }
 
   // Check if exists (if we need it to), or that it doesn't (if it shouldn't).