Ensure --strict-equality works correctly with partial types

Author: A5rocks

mypy/checker.py

@@ -617,7 +617,7 @@ def accept_loop(
             # If necessary, reset the modified options and make up for the postponed error checks:
             if warn_redundant:
                 self.options.enabled_error_codes.add(codes.REDUNDANT_EXPR)
-            if self.options.warn_unreachable or warn_redundant:
+            if self.options.warn_unreachable or warn_redundant or self.options.strict_equality:
                 with self.binder.frame_context(can_skip=True, break_frame=2, continue_frame=1):
                     if on_enter_body is not None:
                         on_enter_body()

test-data/unit/check-errorcodes.test

@@ -519,6 +519,11 @@ if int() != str():  # E: Non-overlapping equality check (left operand type: "int
     pass
 if int() is str():  # E: Non-overlapping identity check (left operand type: "int", right operand type: "str")  [comparison-overlap]
     pass
+
+x = int()
+while True:
+    if x is str():  # E: Non-overlapping identity check (left operand type: "int", right operand type: "str")  [comparison-overlap]
+        pass
 [builtins fixtures/primitives.pyi]
 
 [case testErrorCodeMissingModule]