from the really-stupid-bug department: uppercase literals should match

uppercase strings also when the IGNORECASE flag is set (bug #128899)

(also added test cases for recently fixed bugs to the regression suite
-- or in other words, check in re_tests.py too...)

Lib/sre_compile.py

@@ -23,9 +23,10 @@ def _compile(code, pattern, flags):
         if op in (LITERAL, NOT_LITERAL):
             if flags & SRE_FLAG_IGNORECASE:
                 emit(OPCODES[OP_IGNORE[op]])
+                emit(_sre.getlower(av, flags))
             else:
                 emit(OPCODES[op])
-            emit(av)
+                emit(av)
         elif op is IN:
             if flags & SRE_FLAG_IGNORECASE:
                 emit(OPCODES[OP_IGNORE[op]])