security-guidance: pass core.quotePath=false to diff feeders (#2082)

Fixes anthropics/claude-plugins-official#2082 — diff feeders use git's
default quotePath setting, which C-quotes any path with a non-ASCII
byte. The downstream parsers in gitutil.parse_diff_into_files /
gitutil.extract_file_paths_from_diff match the diff header with
`re.match(r'^a/(.+?) b/(.+)$', ...)`, which only sees the raw
`a/path b/path` form. The C-quoted `"a/\303\201vila/..."` form
slips past the regex, the `continue` fires, and the file is silently
dropped from review.

Effect: a vulnerable file like `Ávila/payment.py` with
`os.system('curl ' + user_input)` never reaches the LLM reviewer.
False negative in exactly the direction the plugin exists to catch.

Sibling of #2056 / #2075: those fixed the UTF-8 decode of the
subprocess output (text=True crashed the reader thread on Windows
cp1252). This one fixes the diff-feeder commands themselves — the
name-only helpers (_git_name_only, _git_status_porcelain) already
pass core.quotePath=false for this exact reason; the diff-text
feeders were the holdouts.

Fix: add `-c core.quotePath=false` to 4 git invocations:

  - gitutil._git_diff_range            (push-sweep feed)
  - gitutil.get_git_diff                (Stop-hook feed)
  - security_reminder_hook commit-review `git diff` (amend delta)
  - security_reminder_hook commit-review `git show`  (post-amend)

With the flag, git emits raw UTF-8 in the diff header
(`a/Ávila/payment.py`), the regex matches, and both files (the
non-ASCII vulnerable one + any ASCII control file) flow through to
review correctly.

Verified locally on macOS Python 3.13:

  - py_compile clean on both files.
  - Existing 45 smoke + extensibility tests still pass.
  - 8 new tests in test_diff_parser_non_ascii.py (added to internal
    test suite at sg-staging/tests/, not in this PR):

      * 2 static-shape: gitutil._git_diff_range and get_git_diff both
        contain `core.quotePath=false` in their source.
      * 2 commit-review static: every subprocess.run in
        handle_commit_review_posttooluse that mentions `"diff"` or
        `"show"` also passes the flag. Catches the regression
        class where a new diff/show call site is added without
        plumbing the flag through.
      * 4 end-to-end with a real git repo containing a
        `Ávila/payment.py` baseline-and-edit:
          - WITHOUT flag: header is C-quoted, both parsers drop the
            non-ASCII file (demonstrates the bug).
          - WITH flag: header is raw UTF-8, both parsers see the file.
          - parse_diff_into_files (the other parse path) also keeps
            the file with the flag.
          - get_git_diff end-to-end produces unquoted output whose
            file list includes the non-ASCII path.

  - 53/53 pass total (45 existing + 8 new) in 3.41s.

NOT verified end-to-end with a real CC commit-review fire on a
non-ASCII path. The static-shape tests catch the regression and the
end-to-end git-repo tests pin parser behavior, but the actual
LLM-review-with-vuln-found path requires runtime verification against
an Anthropic-API-credentialed CC session.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

plugins/security-guidance/hooks/gitutil.py

@@ -199,8 +199,15 @@ def _git_diff_range(repo_root, base, head="HEAD"):
     them reviewed — otherwise unreviewed commits get permanently silenced.
     """
     try:
+        # core.quotePath=false makes git emit raw UTF-8 in `diff --git a/... b/...`
+        # headers instead of C-quoting non-ASCII path bytes (`"a/\303\201vila/..."`
+        # vs `a/Ávila/...`). The downstream `re.match(r'^a/(.+?) b/(.+)$', ...)`
+        # in parse_diff_into_files / extract_file_paths_from_diff matches the
+        # raw form only — quoted headers slip past and the entire file is
+        # silently dropped from review. See #2082 (sibling of #2056 / #2075).
         r = subprocess.run(
-            [*GIT_CMD, "diff", "-p", "--no-color", "--no-ext-diff", base, head],
+            [*GIT_CMD, "-c", "core.quotePath=false",
+             "diff", "-p", "--no-color", "--no-ext-diff", base, head],
             cwd=repo_root, capture_output=True, timeout=30,
         )
         if r.returncode != 0:
@@ -436,7 +443,11 @@ def get_git_diff(cwd, baseline_sha, full_context=False, paths=None, untracked_pa
         # change exists to fix.
         return ""
 
-    cmd = [*GIT_CMD, "diff", "--no-color", "--no-ext-diff", baseline_sha] + (["--unified=99999"] if full_context else []) + pathspec
+    # core.quotePath=false: emit raw UTF-8 in `diff --git a/... b/...` headers
+    # so non-ASCII paths aren't C-quoted past the downstream parse_diff_into_files
+    # regex. See #2082 (sibling of #2056 / #2075).
+    cmd = [*GIT_CMD, "-c", "core.quotePath=false",
+           "diff", "--no-color", "--no-ext-diff", baseline_sha] + (["--unified=99999"] if full_context else []) + pathspec
     try:
         with _temp_index(cwd, untracked_paths) as env:
             # env is None when no index could be found (bare repo / not a

plugins/security-guidance/hooks/security_reminder_hook.py

@@ -1118,16 +1118,21 @@ def handle_commit_review_posttooluse(input_data):
     resolved = 0
     for sha in shas:
         try:
+            # core.quotePath=false: emit raw UTF-8 in `diff --git a/... b/...`
+            # headers so non-ASCII paths aren't C-quoted past the downstream
+            # parse_diff_into_files regex (sibling of #2056 / #2075). See #2082.
             if pre_amend_sha:
                 # Delta review: pre-amend → post-amend. `git diff` (not show)
                 # so the output is a pure unified diff with no commit header.
                 result = subprocess.run(
-                    [*GIT_CMD, "diff", "--no-color", "--no-ext-diff", pre_amend_sha, sha, "--"],
+                    [*GIT_CMD, "-c", "core.quotePath=false",
+                     "diff", "--no-color", "--no-ext-diff", pre_amend_sha, sha, "--"],
                     cwd=repo_root, capture_output=True, timeout=15
                 )
             else:
                 result = subprocess.run(
-                    [*GIT_CMD, "show", "-p", "--no-color", "--no-ext-diff", sha, "--"],
+                    [*GIT_CMD, "-c", "core.quotePath=false",
+                     "show", "-p", "--no-color", "--no-ext-diff", sha, "--"],
                     cwd=repo_root, capture_output=True, timeout=15
                 )
         except (subprocess.TimeoutExpired, FileNotFoundError, OSError) as e: