[XAM] Fixed issue with XamContentCreate reassigning already assigned symlinks

src/xenia/vfs/virtual_file_system.cc

@@ -56,6 +56,15 @@ bool VirtualFileSystem::UnregisterDevice(const std::string_view path) {
 bool VirtualFileSystem::RegisterSymbolicLink(const std::string_view path,
                                              const std::string_view target) {
   auto global_lock = global_critical_region_.Acquire();
+  auto it = std::find_if(
+      symlinks_.cbegin(), symlinks_.cend(),
+      [&](const auto& s) { return xe::utf8::equal_case(path, s.first); });
+  if (it != symlinks_.end()) {
+    XELOGE("Trying to re-register already registered symbolic link: {} => {}",
+           path, target);
+    return false;
+  }
+
   symlinks_.insert({std::string(path), std::string(target)});
   XELOGD("Registered symbolic link: {} => {}", path, target);
 
@@ -76,6 +85,14 @@ bool VirtualFileSystem::UnregisterSymbolicLink(const std::string_view path) {
   return true;
 }
 
+bool VirtualFileSystem::IsSymbolicLinkRegistered(const std::string_view path) {
+  auto it = std::find_if(
+      symlinks_.cbegin(), symlinks_.cend(),
+      [&](const auto& s) { return xe::utf8::equal_case(path, s.first); });
+
+  return it != symlinks_.cend();
+}
+
 bool VirtualFileSystem::FindSymbolicLink(const std::string_view path,
                                          std::string& target) {
   auto it = std::find_if(