Summary of Changes

Hello, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request addresses a subtle but critical bug in how trust hash and monorepo marker files were named, which could lead to hash collisions and compromise the paranoid mode's trust verification. The issue stemmed from PathBuf::with_extension incorrectly parsing filenames that already contained dots. The solution introduces a dedicated helper function to ensure extensions are always appended, thereby preventing filename conflicts and restoring the integrity of the trust system.

Highlights

• Bug Fix: Resolved a critical bug where PathBuf::with_extension caused trust hash and monorepo marker filename collisions due to incorrect handling of dots in hashed filenames.
• New Helper Function: Introduced a new helper function, with_appended_extension, to correctly append extensions to filenames without replacing existing parts of the name.
• Code Refactor: Updated all relevant calls to use the new with_appended_extension helper for hash and monorepo file paths, ensuring correct path generation.

Greptile Summary

This PR fixes a trust-hash filename collision in mise's paranoid-mode trust verification. Path::with_extension("hash") was replacing everything after the last dot in a trust filename (e.g. infra-mise.toml-a1b2c3d4 → infra-mise.hash), meaning every config file that shared the same parent-directory leaf name (e.g. /projectA/infra/mise.toml and /projectB/infra/mise.toml) would map to the same .hash/.monorepo file, silently invalidating or mixing up trust state. The fix introduces with_appended_extension, a thin helper that appends .{ext} to the full OsString path instead of replacing the last component, and applies it consistently across all four call-sites (trust, untrust, mark_as_monorepo_root, trust_file_hash, and the monorepo-root walk in is_trusted).

Key changes:

• New with_appended_extension helper preserves the full filename when adding .hash/.monorepo suffixes
• All four previous Path::with_extension call-sites updated consistently
• untrust now also removes the corresponding .hash and .monorepo auxiliary files (previously it only removed the primary trust symlink)
• One-time migration impact documented in code: existing users in paranoid mode will need to re-run mise trust after upgrading because old .hash files (written under the buggy naming) will no longer be found
• Unit test added for the helper function

Confidence Score: 4/5

• Safe to merge — the fix is correct, all callsites are consistently updated, and the migration impact is documented.
• The PR surgically fixes a real collision bug with a minimal, well-scoped helper. All four with_extension callsites are updated, the untrust cleanup is improved, and the with_appended_extension function is unit-tested. One point withheld because the change silently invalidates existing .hash files for users in paranoid mode (a one-time re-trust is needed), which is a meaningful user-visible behavior change, though it is acknowledged in the code comments.
• No files require special attention — the single changed file is clean and consistent.

Important Files Changed

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    A[mise trust path] --> B[trust_path: hash path filename]
    B --> C["hashed_path = ~/.mise/trusted-configs/dir-file-HASH"]
    C --> D[write symlink at hashed_path]
    D --> E{paranoid mode?}
    E -- yes --> F["with_appended_extension(hashed_path, 'hash')"]
    F --> G["writes ~/.mise/trusted-configs/dir-file-HASH.hash"]
    E -- no --> Z[done]

    H[mise untrust path] --> I[trust_path]
    I --> J[remove hashed_path if exists]
    J --> K["with_appended_extension(hashed_path, 'hash') → remove .hash file"]
    K --> L["with_appended_extension(hashed_path, 'monorepo') → remove .monorepo file"]

    M[is_trusted path] --> N{paranoid?}
    N -- yes --> O["trust_file_hash: with_appended_extension(trust_path, 'hash')"]
    O --> P[read stored hash, compare with current file hash]
    N -- no --> Q{monorepo walk?}
    Q -- yes --> R["with_appended_extension(trust_path dir, 'monorepo') exists?"]
    R -- yes --> S[trusted]
    R -- no --> T[walk to parent dir]

_{Last reviewed commit: e09b622}