From 5b52987b8f7cd1a75e8b17aa7f3c353bf7838eb4 Mon Sep 17 00:00:00 2001
From: Bas van Beek <b.f.van.beek@vu.nl>
Date: Tue, 12 Jan 2021 21:26:28 +0100
Subject: [PATCH] BUG: Fix an `issubclass` failure for protocols with
 overloaded methods

---
 mypy/subtypes.py                    |  2 +-
 test-data/unit/check-protocols.test | 13 ++++++++++++-
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/mypy/subtypes.py b/mypy/subtypes.py
index 81726b1f9884..c6c62d208fb2 100644
--- a/mypy/subtypes.py
+++ b/mypy/subtypes.py
@@ -712,7 +712,7 @@ def non_method_protocol_members(tp: TypeInfo) -> List[str]:
 
     for member in tp.protocol_members:
         typ = get_proper_type(find_member(member, instance, instance))
-        if not isinstance(typ, CallableType):
+        if not isinstance(typ, (Overloaded, CallableType)):
             result.append(member)
     return result
 
diff --git a/test-data/unit/check-protocols.test b/test-data/unit/check-protocols.test
index 30d33b917123..b264d4d8b0e9 100644
--- a/test-data/unit/check-protocols.test
+++ b/test-data/unit/check-protocols.test
@@ -2197,7 +2197,7 @@ y: PBad = None  # E: Incompatible types in assignment (expression has type "None
 [out]
 
 [case testOnlyMethodProtocolUsableWithIsSubclass]
-from typing import Protocol, runtime_checkable, Union, Type
+from typing import Protocol, runtime_checkable, Union, Type, Sequence, overload
 @runtime_checkable
 class P(Protocol):
     def meth(self) -> int:
@@ -2219,6 +2219,17 @@ if issubclass(cls, P):
     reveal_type(cls)  # N: Revealed type is 'Type[__main__.C]'
 else:
     reveal_type(cls)  # N: Revealed type is 'Type[__main__.E]'
+
+@runtime_checkable
+class POverload(Protocol):
+    @overload
+    def meth(self, a: int) -> float: ...
+    @overload
+    def meth(self, a: str) -> Sequence[float]: ...
+    def meth(self, a):
+        pass
+
+reveal_type(issubclass(int, POverload))  # N: Revealed type is 'builtins.bool'
 [builtins fixtures/isinstance.pyi]
 [typing fixtures/typing-full.pyi]
 [out]