`resolve_base_dir` detects worktrees dir inside repo when it's actually not

[blizzy78]

If gtr.worktrees.dir or GTR_WORKTREES_DIR are set to .., resolve_base_dir will detect the worktrees dir "inside" the repo when it's actually not.

The culprit seems to be this conditional:

if [[ "$base_dir" == "$repo_root"/* ]]; then

where /* includes directory entries . and ..

[blizzy78]

@coderabbitai do it

[ParthGandhi]

@coderabbitai plan

[coderabbitai]

Implementation Plan

Approach

Fix a bug where resolve_base_dir incorrectly identifies a worktrees directory as being inside the repository when the configured path uses .. (parent directory) notation. The issue occurs because bash pattern matching evaluates path strings before they're canonicalized, causing paths like ../worktrees to incorrectly match the repository path pattern.

Observations

This is a bash-based git worktree management tool with a modular structure. The core functionality lives in lib/core.sh, which includes the resolve_base_dir function responsible for resolving and validating worktree directory locations. Path canonicalization is handled by the canonicalize_path function that uses cd -P to resolve symlinks and normalize paths. Configuration is managed through lib/config.sh, and the codebase currently has no automated test infrastructure.

Assumptions

Assumption 1: How to handle path normalization for non-existent directories?

Options Considered:

• Add a text-based path normalization function that manually processes .. and . components
• Use external utilities like realpath -m or readlink -m with fallback logic
• Canonicalize the parent directory and append the basename for non-existent paths

Chosen Option: Canonicalize the parent directory and append the basename for non-existent paths

Rationale: This approach reuses the existing canonicalize_path function, aligns with the codebase's bash-centric patterns, requires minimal code changes, and handles the common case where the parent directory exists even if the worktrees directory itself hasn't been created yet. Developers will find this approach intuitive since it builds on existing patterns rather than introducing new utilities or complex string manipulation.

💡 User Tips

Regenerate the plan with different choices with @coderabbitai <feedback>.

Plan

Phase 1: Fix Path Canonicalization Timing

This phase addresses the root cause by ensuring paths are fully normalized before the containment check runs, regardless of whether the worktrees directory exists.

Task 1: Add Path Normalization for Non-Existent Directories

Enhance the path resolution logic in lib/core.sh within the resolve_base_dir function to handle non-existent paths.

• Add logic after the tilde expansion block (after line 61) but before the existing canonicalization block (before line 71)
• When base_dir is set but doesn't exist as a directory, canonicalize its parent directory using the existing canonicalize_path function
• Extract the parent path using dirname and the final component using basename
• If the parent directory exists and can be canonicalized, reconstruct base_dir as the canonicalized parent plus the basename
• This ensures paths like /repo/../worktrees are normalized to /worktrees even when the worktrees directory doesn't exist yet

Task 2: Verify Canonicalization Happens Before Pattern Matching

Ensure the containment check uses canonicalized paths.

• Confirm that by the time execution reaches the pattern matching check (currently line 91: [[ "$base_dir" == "$canonical_repo_root"/* ]]), the base_dir variable has been normalized through either the existing canonicalization block (for existing directories) or the new normalization logic (for non-existent directories)
• The existing conditional check [ -d "$base_dir" ] before the pattern match remains appropriate since it prevents false warnings when the path is being normalized but hasn't been created yet

🤖 Prompt for AI agents

Fix the path canonicalization timing issue in `resolve_base_dir` to ensure paths
are normalized before containment checks.

In `lib/core.sh`, modify the `resolve_base_dir` function:
- Add path normalization logic for non-existent directories after tilde
expansion but before existing canonicalization
- When `base_dir` is set but doesn't exist, use `dirname` to get the parent path
and `basename` to get the final component
- Canonicalize the parent directory using the existing `canonicalize_path`
function
- Reconstruct `base_dir` by combining the canonicalized parent with the basename
- Ensure this normalization happens before the pattern matching check that
validates worktrees aren't inside the repository
- Verify the containment check receives canonicalized paths from either the
existing block (for existing dirs) or new logic (for non-existent dirs)

Phase 2: Validate Fix Correctness

This phase ensures the fix works correctly across different scenarios without breaking existing functionality.

Task 1: Add Inline Documentation

Document the path normalization logic and the bug fix in lib/core.sh.

• Add comments explaining why the parent directory canonicalization is necessary for non-existent paths
• Document the specific case being handled: relative paths with .. that would incorrectly match the repository pattern before normalization
• Note that this handles the gap between configuration parsing and directory creation

Task 2: Manual Testing Verification

Since there's no automated test infrastructure, document the manual testing approach for developers.

• Update CLAUDE.md or relevant documentation with test scenarios to verify the fix
• Test cases should include: setting gtr.worktrees.dir = .., setting it to ../worktrees, using both environment variable and git config, and testing with both existing and non-existing worktrees directories
• Verify that the warning about worktrees being inside the repository is correctly suppressed when using .. paths that resolve outside the repo
• Verify that legitimate warnings still appear when worktrees are actually configured inside the repository

🤖 Prompt for AI agents

Document the fix and provide manual testing guidance.

In `lib/core.sh`:
- Add inline comments explaining the parent directory canonicalization for
non-existent paths
- Document that this fixes relative paths with `..` incorrectly matching
repository patterns before normalization
- Note this handles the gap between config parsing and directory creation

In `CLAUDE.md` or relevant documentation:
- Add manual test scenarios including: `gtr.worktrees.dir = ..`, `../worktrees`,
environment variable vs git config, existing vs non-existing directories
- Document expected behavior: warnings suppressed for `..` paths resolving
outside repo, warnings still shown for paths actually inside repo

---

🚀 Next Steps

🤖 All AI agent prompts combined

Task: 1

Fix the path canonicalization timing issue in `resolve_base_dir` to ensure paths
are normalized before containment checks.

In `lib/core.sh`, modify the `resolve_base_dir` function:
- Add path normalization logic for non-existent directories after tilde
expansion but before existing canonicalization
- When `base_dir` is set but doesn't exist, use `dirname` to get the parent path
and `basename` to get the final component
- Canonicalize the parent directory using the existing `canonicalize_path`
function
- Reconstruct `base_dir` by combining the canonicalized parent with the basename
- Ensure this normalization happens before the pattern matching check that
validates worktrees aren't inside the repository
- Verify the containment check receives canonicalized paths from either the
existing block (for existing dirs) or new logic (for non-existent dirs)
===============================================================================

Task: 2

Document the fix and provide manual testing guidance.

In `lib/core.sh`:
- Add inline comments explaining the parent directory canonicalization for
non-existent paths
- Document that this fixes relative paths with `..` incorrectly matching
repository patterns before normalization
- Note this handles the gap between config parsing and directory creation

In `CLAUDE.md` or relevant documentation:
- Add manual test scenarios including: `gtr.worktrees.dir = ..`, `../worktrees`,
environment variable vs git config, existing vs non-existing directories
- Document expected behavior: warnings suppressed for `..` paths resolving
outside repo, warnings still shown for paths actually inside repo

💡 Iterate on the plan with: @coderabbitai <feedback>

Example Feedback
- @coderabbitai You can skip phase 3. Add a simple unit test case for phase 2.
- @coderabbitai For assumption 1 go ahead with option 3 and replan.