fix(security): deny unresolvable paths and enable Git bash detection on Windows

src/path_scope.py

@@ -72,7 +72,15 @@ class WorkspacePathScope:
             path = base / path
         expanded = self._expand_glob(path)
         for expanded_path in expanded:
+            try:
                 resolved = expanded_path.resolve(strict=False)
+            except (OSError, ValueError, RuntimeError):
+                return PathScopeDecision(
+                    False,
+                    'path cannot be resolved or is invalid',
+                    str(candidate),
+                    str(expanded_path),
+                )
             if not any(_is_relative_to(resolved, root) for root in self.roots):
                 return PathScopeDecision(
                     False,
@@ -80,7 +88,16 @@ class WorkspacePathScope:
                     str(candidate),
                     str(resolved),
                 )
-        return PathScopeDecision(True, 'path is inside workspace scope', str(candidate), str(expanded[0].resolve(strict=False)))
+        try:
+            final_resolved = str(expanded[0].resolve(strict=False))
+        except (OSError, ValueError, RuntimeError):
+            return PathScopeDecision(
+                False,
+                'path cannot be resolved or is invalid',
+                str(candidate),
+                str(expanded[0]),
+            )
+        return PathScopeDecision(True, 'path is inside workspace scope', str(candidate), final_resolved)
 
     def _expand_glob(self, path: Path) -> tuple[Path, ...]:
         path_text = str(path)

tests/test_pre_push_hook_contract.py

@@ -1,22 +1,37 @@
-from __future__ import annotations
-
-import unittest
-import os
-
-def require_bash() -> bool:
-    import shutil
-    bash = shutil.which('bash')
-    if os.name == 'nt':
-        return False
-    return bash is not None
-
-
 import os
+import shutil
 import subprocess
 import unittest
 from pathlib import Path
 
 
+def get_bash_executable() -> str | None:
+    if os.name == 'nt':
+        for candidate in (
+            r'C:\Program Files\Git\bin\bash.exe',
+            r'C:\Program Files\Git\usr\bin\bash.exe',
+            r'C:\Program Files (x86)\Git\bin\bash.exe',
+            os.path.expandvars(r'%LOCALAPPDATA%\Programs\Git\bin\bash.exe'),
+        ):
+            if os.path.exists(candidate):
+                return candidate
+    bash = shutil.which('bash')
+    if bash and 'WindowsApps' not in bash:
+        return bash
+    return None
+
+
+def require_bash() -> bool:
+    bash = get_bash_executable()
+    if not bash:
+        return False
+    try:
+        res = subprocess.run([bash, '-c', 'echo 1'], capture_output=True, text=True, timeout=2)
+        return res.returncode == 0
+    except Exception:
+        return False
+
+
 REPO_ROOT = Path(__file__).resolve().parents[1]
 PRE_PUSH_HOOK = REPO_ROOT / '.github' / 'hooks' / 'pre-push'
 
@@ -24,11 +39,12 @@ PRE_PUSH_HOOK = REPO_ROOT / '.github' / 'hooks' / 'pre-push'
 class PrePushHookContractTests(unittest.TestCase):
     @unittest.skipUnless(require_bash(), 'Requires bash')
     def test_skip_escape_hatch_exits_successfully_with_stderr_notice(self) -> None:
+        bash_cmd = get_bash_executable() or 'bash'
         env = os.environ.copy()
         env['SKIP_CLAW_PRE_PUSH_BUILD'] = '1'
 
         result = subprocess.run(
-            ['bash', str(PRE_PUSH_HOOK)],
+            [bash_cmd, str(PRE_PUSH_HOOK)],
             cwd=REPO_ROOT,
             env=env,
             check=True,

tests/test_roadmap_helpers.py

@@ -16,18 +16,38 @@ DOGFOOD_PROBE = REPO_ROOT / 'scripts' / 'dogfood-probe.py'
 
 import sys
 
-def require_bash() -> bool:
+def get_bash_executable() -> str | None:
     import os
-    import shutil
-    bash = shutil.which('bash')
     if os.name == 'nt':
-        # On Windows, 'bash' often resolves to WSL which fails if not configured
+        for candidate in (
+            r'C:\Program Files\Git\bin\bash.exe',
+            r'C:\Program Files\Git\usr\bin\bash.exe',
+            r'C:\Program Files (x86)\Git\bin\bash.exe',
+            os.path.expandvars(r'%LOCALAPPDATA%\Programs\Git\bin\bash.exe'),
+        ):
+            if os.path.exists(candidate):
+                return candidate
+    bash = shutil.which('bash')
+    if bash and 'WindowsApps' not in bash:
+        return bash
+    return None
+
+
+def require_bash() -> bool:
+    bash = get_bash_executable()
+    if not bash:
         return False
-    return bash is not None
+    try:
+        res = subprocess.run([bash, '-c', 'echo 1'], capture_output=True, text=True, timeout=2)
+        return res.returncode == 0
+    except Exception:
+        return False
+
 
 def run_next_id(roadmap: Path, script: Path = NEXT_ID) -> subprocess.CompletedProcess[str]:
+    bash_cmd = get_bash_executable() or 'bash'
     return subprocess.run(
-        ['bash', str(script), str(roadmap)],
+        [bash_cmd, str(script), str(roadmap)],
         cwd=REPO_ROOT,
         capture_output=True,
         text=True,

tests/test_security_scope.py

@@ -166,6 +166,19 @@ class WorkspacePathScopeTests(unittest.TestCase):
                 self.assertFalse(decision.allowed)
                 self.assertIn('outside workspace scope', decision.reason)
 
+    def test_unresolvable_path_raises_oserror_is_denied(self) -> None:
+        """Verify that paths raising OSError during resolve() are explicitly denied."""
+        with tempfile.TemporaryDirectory() as tmp:
+            workspace = Path(tmp) / 'workspace'
+            workspace.mkdir()
+            scope = WorkspacePathScope.from_root(workspace)
+
+            from unittest.mock import patch
+            with patch.object(Path, 'resolve', side_effect=OSError('dangling symlink or filesystem error')):
+                decision = scope.validate_path(str(workspace / 'broken_link.txt'))
+                self.assertFalse(decision.allowed)
+                self.assertIn('cannot be resolved', decision.reason)
+
     def test_glob_expansion_must_stay_inside_workspace(self) -> None:
         with tempfile.TemporaryDirectory() as tmp:
             root = Path(tmp)