fix error reporter and testsuite in 3.11.4+ (#775)

Author: asottile

pyflakes/reporter.py

@@ -56,8 +56,9 @@ def syntaxError(self, filename, msg, lineno, offset, text):
         else:
             line = text.splitlines()[-1]
 
+        # lineno might be None if the error was during tokenization
         # lineno might be 0 if the error came from stdin
-        lineno = max(lineno, 1)
+        lineno = max(lineno or 0, 1)
 
         if offset is not None:
             # some versions of python emit an offset of -1 for certain encoding errors

pyflakes/test/test_api.py

@@ -621,8 +621,12 @@ def test_misencodedFileUTF16(self):
 x = "%s"
 """ % SNOWMAN).encode('utf-16')
         with self.makeTempFile(source) as sourcePath:
-            self.assertHasErrors(
-                sourcePath, [f"{sourcePath}: problem decoding source\n"])
+            if sys.version_info < (3, 11, 4):
+                expected = f"{sourcePath}: problem decoding source\n"
+            else:
+                expected = f"{sourcePath}:1: source code string cannot contain null bytes\n"  # noqa: E501
+
+            self.assertHasErrors(sourcePath, [expected])
 
     def test_checkRecursive(self):
         """