[syntax-error] Fix a crash when the line and column can't be retrieved

Closes #3860

Author: Pierre-Sassoulas

pylint/lint/pylinter.py

@@ -692,11 +692,9 @@ def _check_files(
                     )
                     msg = get_fatal_error_message(file.filepath, template_path)
                     if isinstance(ex, AstroidError):
-                        symbol = "astroid-error"
-                        self.add_message(symbol, args=(file.filepath, msg))
+                        self.add_message("astroid-error", args=(file.filepath, msg))
                     else:
-                        symbol = "fatal"
-                        self.add_message(symbol, args=msg)
+                        self.add_message("fatal", args=msg)
 
     def _check_file(
         self,
@@ -918,7 +916,8 @@ def get_ast(
                 "syntax-error",
                 line=getattr(ex.error, "lineno", 0),
                 col_offset=getattr(ex.error, "offset", None),
-                args=str(ex.error),
+                args=ex.error,
+                confidence=HIGH,
             )
         except astroid.AstroidBuildingError as ex:
             self.add_message("parse-error", args=ex)

tests/functional/s/syntax/syntax_error.txt

@@ -1 +1,2 @@
-syntax-error:1:10:None:None::invalid syntax (<unknown>, line 1):UNDEFINED
+syntax-error:1:10:None:None::"Parsing Python code failed:
+invalid syntax (<unknown>, line 1)":HIGH

tests/test_self.py

@@ -27,6 +27,7 @@
 from unittest.mock import patch
 
 import pytest
+from astroid import PY310_PLUS
 from py._path.local import LocalPath  # type: ignore[import]
 
 from pylint import extensions, modify_sys_path
@@ -569,10 +570,11 @@ def foobar(arg):
                     expected_output=expected,
                 )
 
-    def test_stdin_syntaxerror(self) -> None:
+    def test_stdin_syntax_error(self) -> None:
         expected_output = (
             "************* Module a\n"
-            "a.py:1:4: E0001: invalid syntax (<unknown>, line 1) (syntax-error)"
+            "a.py:1:4: E0001: Parsing Python code failed:\n"
+            "invalid syntax (<unknown>, line 1) (syntax-error)"
         )
 
         with mock.patch(
@@ -584,6 +586,18 @@ def test_stdin_syntaxerror(self) -> None:
             )
             assert mock_stdin.call_count == 1
 
+    @pytest.mark.skipif(
+        PY310_PLUS, reason="Not a syntax error for python 3.10 or superior"
+    )
+    def test_astroid_syntax_error(self, tmp_path) -> None:
+        file_path = tmp_path / "a.py"
+        with open(file_path, "w", encoding="utf8") as f:
+            f.write("# encoding=UTF-9\n")
+        self._test_output(
+            [str(file_path), "--disable=all", "--enable=syntax-error"],
+            expected_output="a.py': UTF-9 (syntax-error)",
+        )
+
     def test_version(self) -> None:
         def check(lines: list[str]) -> None:
             assert lines[0].startswith("pylint ")