From 3f531e14ed5c6324d99e2e7fe956725a683265d7 Mon Sep 17 00:00:00 2001
From: STerliakov <terlya.stas@gmail.com>
Date: Wed, 5 Feb 2025 01:49:19 +0100
Subject: [PATCH 1/4] Normalize tuple fallback to tuple[Any, ...] in
 constructor if it isn't special

---
 mypy/checker.py | 5 -----
 mypy/types.py   | 6 ++++++
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/mypy/checker.py b/mypy/checker.py
index 999d75678aa45..066e929c52009 100644
--- a/mypy/checker.py
+++ b/mypy/checker.py
@@ -8484,11 +8484,6 @@ def visit_type_var(self, t: TypeVarType) -> bool:
         # multi-step type inference.
         return t.id.is_meta_var()
 
-    def visit_tuple_type(self, t: TupleType, /) -> bool:
-        # Exclude fallback to avoid bogus "need type annotation" errors
-        # TODO: Maybe erase plain tuples used as fallback in TupleType constructor?
-        return self.query_types(t.items)
-
 
 class SetNothingToAny(TypeTranslator):
     """Replace all ambiguous Uninhabited types with Any (to avoid spurious extra errors)."""
diff --git a/mypy/types.py b/mypy/types.py
index f700be8871162..76e4ad03ba276 100644
--- a/mypy/types.py
+++ b/mypy/types.py
@@ -2415,6 +2415,12 @@ def __init__(
         implicit: bool = False,
     ) -> None:
         super().__init__(line, column)
+        if fallback.type and fallback.type.fullname == "builtins.tuple":
+            assert len(fallback.args) == 1
+            if not isinstance(fallback.args[0], AnyType):
+                fallback = fallback.copy_modified(
+                    args=[AnyType(TypeOfAny.implementation_artifact)]
+                )
         self.partial_fallback = fallback
         self.items = items
         self.implicit = implicit

From 749f9560a247b0f55f471eb91dee1523d4e5bf7d Mon Sep 17 00:00:00 2001
From: STerliakov <terlya.stas@gmail.com>
Date: Wed, 5 Feb 2025 02:51:20 +0100
Subject: [PATCH 2/4] Fix own typing

---
 mypy/types.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/mypy/types.py b/mypy/types.py
index 76e4ad03ba276..26c3e48365e06 100644
--- a/mypy/types.py
+++ b/mypy/types.py
@@ -2417,7 +2417,9 @@ def __init__(
         super().__init__(line, column)
         if fallback.type and fallback.type.fullname == "builtins.tuple":
             assert len(fallback.args) == 1
-            if not isinstance(fallback.args[0], AnyType):
+            if not isinstance(fallback.args[0], ProperType) or not isinstance(
+                fallback.args[0], AnyType
+            ):
                 fallback = fallback.copy_modified(
                     args=[AnyType(TypeOfAny.implementation_artifact)]
                 )

From a3bd40f1a40d0633c22a593e976bf5b1ebb6ad0e Mon Sep 17 00:00:00 2001
From: STerliakov <terlya.stas@gmail.com>
Date: Wed, 5 Feb 2025 03:02:37 +0100
Subject: [PATCH 3/4] That should be special_form

---
 mypy/messages.py | 1 +
 mypy/types.py    | 4 +---
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/mypy/messages.py b/mypy/messages.py
index 3beb287bcc21c..6b061a379ff64 100644
--- a/mypy/messages.py
+++ b/mypy/messages.py
@@ -2008,6 +2008,7 @@ def untyped_decorated_function(self, typ: Type, context: Context) -> None:
         if isinstance(typ, AnyType):
             self.fail("Function is untyped after decorator transformation", context)
         else:
+            breakpoint()
             self.fail(
                 f'Type of decorated function contains type "Any" ({format_type(typ, self.options)})',
                 context,
diff --git a/mypy/types.py b/mypy/types.py
index 26c3e48365e06..7b65e9a809378 100644
--- a/mypy/types.py
+++ b/mypy/types.py
@@ -2420,9 +2420,7 @@ def __init__(
             if not isinstance(fallback.args[0], ProperType) or not isinstance(
                 fallback.args[0], AnyType
             ):
-                fallback = fallback.copy_modified(
-                    args=[AnyType(TypeOfAny.implementation_artifact)]
-                )
+                fallback = fallback.copy_modified(args=[AnyType(TypeOfAny.special_form)])
         self.partial_fallback = fallback
         self.items = items
         self.implicit = implicit

From 25c13177b4e61545f1ae2a404be0daf77df45341 Mon Sep 17 00:00:00 2001
From: STerliakov <terlya.stas@gmail.com>
Date: Wed, 5 Feb 2025 03:23:26 +0100
Subject: [PATCH 4/4] .

---
 mypy/messages.py | 1 -
 1 file changed, 1 deletion(-)

diff --git a/mypy/messages.py b/mypy/messages.py
index 6b061a379ff64..3beb287bcc21c 100644
--- a/mypy/messages.py
+++ b/mypy/messages.py
@@ -2008,7 +2008,6 @@ def untyped_decorated_function(self, typ: Type, context: Context) -> None:
         if isinstance(typ, AnyType):
             self.fail("Function is untyped after decorator transformation", context)
         else:
-            breakpoint()
             self.fail(
                 f'Type of decorated function contains type "Any" ({format_type(typ, self.options)})',
                 context,