fix

Author: seratch

src/agents/sandbox/workspace_paths.py

@@ -88,7 +88,11 @@ def _coerce_path(cls, value: object) -> str:
     @field_validator("path")
     @classmethod
     def _validate_path(cls, value: str) -> str:
-        if windows_absolute_path(value) is not None:
+        if (windows_path := windows_absolute_path(value)) is not None:
+            native_path = _native_path_from_windows_absolute(windows_path)
+            if native_path is not None:
+                _raise_if_filesystem_root(native_path)
+                return str(native_path)
             raise ValueError("sandbox path grant path must be POSIX absolute")
 
         path = PurePosixPath(posixpath.normpath(value))
@@ -268,6 +272,8 @@ def extra_path_grant_rules(self) -> tuple[tuple[PurePosixPath, bool], ...]:
 
         rules: list[tuple[PurePosixPath, bool]] = []
         for grant in self._extra_path_grants:
+            if windows_absolute_path(grant.path) is not None:
+                raise ValueError("sandbox path grant path must be POSIX absolute")
             root = coerce_posix_path(grant.path)
             _raise_if_filesystem_root(root)
             rules.append((root, grant.read_only))

tests/sandbox/test_workspace_paths.py

@@ -364,7 +364,10 @@ def test_sandbox_extra_path_grant_rules_use_posix_paths() -> None:
     )
 
 
-def test_extra_path_grant_rejects_windows_drive_absolute_path() -> None:
+def test_extra_path_grant_rejects_non_native_windows_drive_absolute_path() -> None:
+    if Path(PureWindowsPath("C:/tmp")).is_absolute():
+        pytest.skip("Windows drive paths are native absolute paths on this host")
+
     for path in (
         PureWindowsPath("C:/tmp"),
         "C:\\tmp",
@@ -387,6 +390,31 @@ def test_extra_path_grant_rejects_windows_drive_absolute_path() -> None:
         }
 
 
+def test_extra_path_grant_accepts_native_windows_drive_absolute_path(
+    tmp_path: Path,
+) -> None:
+    if not Path(PureWindowsPath("C:/tmp")).is_absolute():
+        pytest.skip("Windows drive paths are not native absolute paths on this host")
+
+    grant = SandboxPathGrant(path=str(tmp_path))
+
+    assert Path(grant.path).is_absolute()
+
+
+def test_extra_path_grant_rules_reject_windows_drive_absolute_path() -> None:
+    grant = SandboxPathGrant.model_construct(
+        path="C:/tmp",
+        read_only=False,
+        description=None,
+    )
+    policy = WorkspacePathPolicy(root="/workspace", extra_path_grants=(grant,))
+
+    with pytest.raises(ValueError) as exc_info:
+        policy.extra_path_grant_rules()
+
+    assert str(exc_info.value) == "sandbox path grant path must be POSIX absolute"
+
+
 def test_manifest_serializes_extra_path_grants() -> None:
     manifest = Manifest(
         extra_path_grants=(