Windows: tree-sitter definitions pass fails on ALL files when repo_path contains non-ASCII (CJK / Cyrillic / Arabic / accented Latin / etc.) characters

[maxniu1]

Bug Description

On Windows, when the repo_path passed to index_repository contains Chinese (CJK) characters in directory or file names, the definitions pass (tree-sitter AST parsing) fails on every file — defs=0, calls=0, imports=0, errors=N for all files. The resulting knowledge graph contains only File/Folder/Project nodes with no Function, Class, Method, or Variable nodes, making the index effectively useless for code intelligence.

This is more severe than issue #571 (project name truncation for CJK paths) — that issue is cosmetic, while this one prevents all code-level analysis entirely.

Steps to Reproduce

1. On Windows, create or index a project whose path contains Chinese characters, e.g.:

   F:/项目资产-ProjectAssets/智能体/智能体原型/
   

2. Run:

   codebase-memory-mcp cli index_repository '{"repo_path":"F:/项目资产-ProjectAssets/智能体/智能体原型"}'
   

3. Observe the pipeline log — the definitions pass shows:

   pass=definitions defs=0 calls=0 imports=0 errors=41
   

4. get_architecture returns only File/Folder nodes, zero Function/Class/Method nodes

Expected Behavior

Files at paths with Chinese characters should be parsed by tree-sitter identically to ASCII-only paths. A 41-file TypeScript/JS/CSS project should produce, e.g., defs=200+ with errors=0.

Actual Behavior (Verbose Pipeline Log)

pass=discover files=41
pass=structure nodes=60 edges=58           ← File/Folder tree works fine
pass=definitions defs=0 calls=0 imports=0 errors=41  ← ALL files fail
pass=calls total=0 resolved=0 unresolved=0 errors=41
pass=semantic inherits=0 decorates=0 implements=0 errors=41

Root Cause Verified

Identical file content, copied to an ASCII-only path, indexes correctly:

Test	Path	defs	calls	errors
ASCII path	C:/tmp/core-test.js	30	103	0 ✅
Chinese path	F:/...智能体.../core.js	0	0	41 ❌

The 417-line JS file is byte-identical. The only variable is whether the parent path contains CJK characters. Languages tested: JavaScript, TypeScript (.ts/.tsx), Python, CSS — all fail identically when the path has CJK characters.

Environment

• OS: Windows 10 (64-bit)
• codebase-memory-mcp version: v0.8.1
• Filesystem: NTFS (UTF-8)
• Shell tested: git-bash (MSYS2) — same result via direct Python subprocess call

Suspected Cause

Likely a Windows-specific encoding issue. The structure pass (directory enumeration via FindFirstFileW/FindNextFileW) works because it natively uses wide-char UTF-16 paths. But the definitions pass probably reads file paths as plain char* and passes them to tree-sitter via fopen or similar, which on Windows uses the ANSI codepage (e.g., GBK on zh-CN systems) rather than UTF-8. This causes tree-sitter to receive garbled paths or fail to open file contents for AST parsing.

On Linux/macOS, char* paths in UTF-8 work natively because the filesystem encoding is UTF-8 — this explains why similar issues (#571) were reported but the definitions-pass failure was not caught.

[maxniu1]

Update: This affects ALL non-English Windows users, not just CJK

I want to clarify the actual impact — this is not a Chinese-specific issue. It affects any language with non-ASCII characters on Windows:

Language family	Examples	Affected?
English (ASCII only)	Desktop, project	❌ No
Chinese (CJK)	项目 智能体	✅
Japanese	設定 データ	✅
Korean	프로젝트	✅
Russian (Cyrillic)	Проект Настройки	✅
Arabic	مشروع بيانات	✅
Thai	โครงการ ข้อมูล	✅
Hindi (Devanagari)	परियोजना डेटा	✅
German/French/Spanish	Änderungen état français	✅
Vietnamese	Dự án dữ liệu	✅
Greek	Έργο Ρυθμίσεις	✅
Hebrew	פרויקט נתונים	✅

Key insight: The Windows fopen API uses the system ANSI codepage (e.g., GBK on zh-CN, Shift-JIS on ja-JP, CP1251 on ru-RU) rather than UTF-8. So this will break for ALL users whose filenames contain characters outside ASCII-7 — which is the vast majority of Windows users worldwide.

If a French Windows user has C:\Users\élise\projets\état\config.json, it will also fail.

The actual root cause is the lack of wide-character (UTF-16) file I/O on Windows, not CJK specifically. The structure pass works because FindFirstFileW uses wide chars natively — but fopen/tree-sitter file reading uses the narrow-char API which depends on the active codepage.

[maxniu1]

Fix submitted as PR #637: #637

The fix adds cbm_fopen() — a portable file-open wrapper that uses _wfopen() on Windows (wide-character, UTF-16) and delegates to fopen() on POSIX. Applied to all 3 pipeline files that read source files for tree-sitter parsing.

Tested on a 41-file TypeScript/JS/Python project with CJK directory names. Before: defs=0 errors=41. After: defs=215 errors=0.