Issue #14990: tokenize: correctly fail with SyntaxError on invalid encoding declaration.
diff --git a/Lib/tokenize.py b/Lib/tokenize.py
index f283c6d..59081d3 100644
--- a/Lib/tokenize.py
+++ b/Lib/tokenize.py
@@ -310,7 +310,7 @@
             raise SyntaxError("unknown encoding: " + encoding)
 
         if bom_found:
-            if codec.name != 'utf-8':
+            if encoding != 'utf-8':
                 # This behaviour mimics the Python interpreter
                 raise SyntaxError('encoding problem: utf-8')
             encoding += '-sig'