[BUG] Project path encoding collision: different paths can map to the same project directory

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Claude Code encodes project paths by replacing /, -, and _ all with - when creating project directories under ~/.claude/projects/. This is a lossy encoding that can cause different project paths to map to the same directory.

For example:

• /home/user/project/spec-rl/ → -home-user-project-spec-rl
• /home/user/project/spec/rl/ → -home-user-project-spec-rl

Both produce the same encoded directory name, so two different projects would share memory, settings, and CLAUDE.md.

Similarly with underscores:

• /home/user/my_project/ → -home-user-my-project
• /home/user/my-project/ → -home-user-my-project

What Should Happen?

Each unique project path should map to a unique project directory. The encoding should be injective.

Error Messages/Logs

Steps to Reproduce

1. mkdir -p ~/test/spec-rl && mkdir -p ~/test/spec/rl
2. Run Claude Code in ~/test/spec-rl, save a memory
3. Run Claude Code in ~/test/spec/rl
4. Both sessions use the same ~/.claude/projects/ directory

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.77

Platform

Anthropic API

Operating System

Ubuntu/Debian Linux

Terminal/Shell

Other

Additional Information

Possible fix: use a delimiter that doesn't appear in path components,
e.g. encode each segment separately or use double-dash -- as separator
so /home/user/spec-rl → -home--user--spec-rl
vs /home/user/spec/rl → -home--user--spec--rl.