match: avoid rust fast path if the matcher was tampered with

Otherwise the fast path does not respect the modifications made
by the extension (concretely largefiles, but other extensions can
start using that too)

rust/hg-cpython/src/dirstate/status.rs

@@ -11,7 +11,7 b''
 
 use crate::{dirstate::DirstateMap, exceptions::FallbackError};
 use cpython::{
-    exc::ValueError, ObjectProtocol, PyBytes, PyErr, PyList, PyObject,
+    exc::ValueError, ObjectProtocol, PyBool, PyBytes, PyErr, PyList, PyObject,
     PyResult, PyTuple, Python, PythonObject, ToPyObject,
 };
 use hg::dirstate::status::StatusPath;
@@ -26,8 +26,8 b' use hg::{'
         files::{get_bytes_from_path, get_path_from_bytes},
         hg_path::{HgPath, HgPathBuf},
     },
-    BadMatch, DirstateStatus, IgnorePattern, PatternFileWarning, StatusError,
-    StatusOptions,
+    BadMatch, DirstateStatus, IgnorePattern, PatternError, PatternFileWarning,
+    StatusError, StatusOptions,
 };
 use std::borrow::Borrow;
 
@@ -158,6 +158,18 b' fn extract_matcher('
     py: Python,
     matcher: PyObject,
 ) -> PyResult<Box<dyn Matcher + Sync>> {
+    let tampered = matcher
+        .call_method(py, "was_tampered_with", PyTuple::empty(py), None)?
+        .extract::<PyBool>(py)?
+        .is_true();
+    if tampered {
+        return Err(handle_fallback(
+            py,
+            StatusError::Pattern(PatternError::UnsupportedSyntax(
+                "Pattern matcher was tampered with!".to_string(),
+            )),
+        ));
+    };
     match matcher.get_type(py).name(py).borrow() {
         "alwaysmatcher" => Ok(Box::new(AlwaysMatcher)),
         "nevermatcher" => Ok(Box::new(NeverMatcher)),