Raise syntax-error correctly on invalid encodings (#7553)

Author: DanielNoord

doc/whatsnew/fragments/7522.bugfix

@@ -0,0 +1,3 @@
+Fixed an issue where ``syntax-error`` couldn't be raised on files with invalid encodings.
+
+Closes #7522

pylint/lint/pylinter.py

@@ -1013,9 +1013,12 @@ def get_ast(
                 data, modname, filepath
             )
         except astroid.AstroidSyntaxError as ex:
+            line = getattr(ex.error, "lineno", None)
+            if line is None:
+                line = 0
             self.add_message(
                 "syntax-error",
-                line=getattr(ex.error, "lineno", 0),
+                line=line,
                 col_offset=getattr(ex.error, "offset", None),
                 args=f"Parsing failed: '{ex.error}'",
                 confidence=HIGH,

tests/regrtest_data/invalid_encoding.py

@@ -0,0 +1 @@
+# -*- coding: lala -*-

tests/test_self.py

@@ -1191,6 +1191,11 @@ def test_ignore_path_recursive_current_dir(self) -> None:
                     code=0,
                 )
 
+    def test_syntax_error_invalid_encoding(self) -> None:
+        module = join(HERE, "regrtest_data", "invalid_encoding.py")
+        expected_output = "unknown encoding"
+        self._test_output([module, "-E"], expected_output=expected_output)
+
 
 class TestCallbackOptions:
     """Test for all callback options we support."""