fix: prevent false positive "untyped after decorator transformation" after deferral (#19591)

Fixes #19589

Author: sterliakov

mypy/checker.py

@@ -5502,7 +5502,7 @@ def visit_with_stmt(self, s: WithStmt) -> None:
             self.accept(s.body)
 
     def check_untyped_after_decorator(self, typ: Type, func: FuncDef) -> None:
-        if not self.options.disallow_any_decorated or self.is_stub:
+        if not self.options.disallow_any_decorated or self.is_stub or self.current_node_deferred:
             return
 
         if mypy.checkexpr.has_any_type(typ):

test-data/unit/check-flags.test

@@ -1116,6 +1116,39 @@ def f(x: Any) -> Any:  # E: Function is untyped after decorator transformation
 def h(x):  # E: Function is untyped after decorator transformation
     pass
 [builtins fixtures/list.pyi]
+
+[case testDisallowAnyDecoratedUnannotatedDecoratorDeferred1]
+# flags: --disallow-any-decorated
+from typing import Callable
+
+def d(f: Callable[[int], None]) -> Callable[[int], None]:
+    return f
+
+def wrapper() -> None:
+    if c:
+        @d
+        def h(x):
+            pass
+
+c = [1]
+[builtins fixtures/list.pyi]
+
+[case testDisallowAnyDecoratedUnannotatedDecoratorDeferred2]
+# flags: --disallow-any-decorated
+from typing import Callable
+
+def d(f: Callable[[int], None]) -> Callable[[int], None]:
+    return f
+
+c = 1  # no deferral - check that the previous testcase is valid
+
+def wrapper() -> None:
+    if c:
+        @d
+        def h(x):
+            pass
+[builtins fixtures/list.pyi]
+
 [case testDisallowAnyDecoratedErrorIsReportedOnlyOnce]
 # flags: --disallow-any-decorated