Bug: NewAppendableFile does not record newly created FileState in file_map_

Open Beginner friendly

#1,328 opened on May 23, 2026 0 comments 0 reactions 0 assignees View on GitHub

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Assessment

Difficulty: 2/5
Estimated time: 1-3 hours
Newbie friendliness: 76/100

Issue type: Bug
Clarity: Clearly specified
Activity status: Quiet
Tech stack: cpp
Domain: databases

Research direction

Start in helpers/memenv/memenv.cc at InMemoryEnv::NewAppendableFile, then inspect how file_map_ and FileState are handled by nearby methods. Verify the change with the existing memenv tests if available; done means a newly created appendable file remains associated with its filename in file_map_.

Written by the indexing model from the issue text.

Description

Issue Description

I found a potential bug in helpers/memenv/memenv.cc in the InMemoryEnv::NewAppendableFile method.

Location

helpers/memenv/memenv.cc, lines 276-287

Problem

When a new appendable file is created (i.e., the file does not exist in file_map_), a new FileState object is instantiated and referenced. However, the new FileState is never assigned back to the file_map_, breaking the association between the filename and the FileState object.

Current Code

Status NewAppendableFile(const std::string& fname,
                         WritableFile** result) override {
  MutexLock lock(&mutex_);
  FileState** sptr = &file_map_[fname];
  FileState* file = *sptr;
  if (file == nullptr) {
    file = new FileState();
    file->Ref();
    // BUG: Missing assignment back to file_map_
  }
  *result = new WritableFileImpl(file);
  return Status::OK();
}

Dominant language: C++
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