Now overloads with ambiguous self are handled properly

mypy/checkexpr.py

@@ -1721,6 +1721,7 @@ def infer_overload_return_type(self,
         matches: List[CallableType] = []
         return_types: List[Type] = []
         inferred_types: List[Type] = []
+        self_contains_any = has_any_type(object_type) if object_type is not None else False
         args_contain_any = any(map(has_any_type, arg_types))
 
         for typ in plausible_targets:
@@ -1750,7 +1751,7 @@ def infer_overload_return_type(self,
             if is_match:
                 # Return early if possible; otherwise record info so we can
                 # check for ambiguity due to 'Any' below.
-                if not args_contain_any:
+                if not args_contain_any and not self_contains_any:
                     return ret_type, infer_type
                 matches.append(typ)
                 return_types.append(ret_type)
@@ -1759,7 +1760,9 @@ def infer_overload_return_type(self,
         if len(matches) == 0:
             # No match was found
             return None
-        elif any_causes_overload_ambiguity(matches, return_types, arg_types, arg_kinds, arg_names):
+        elif any_causes_overload_ambiguity(
+                matches, return_types, arg_types, arg_kinds, arg_names,
+                self_contains_any=self_contains_any):
             # An argument of type or containing the type 'Any' caused ambiguity.
             # We try returning a precise type if we can. If not, we give up and just return 'Any'.
             if all_same_types(return_types):
@@ -4394,7 +4397,9 @@ def any_causes_overload_ambiguity(items: List[CallableType],
                                   return_types: List[Type],
                                   arg_types: List[Type],
                                   arg_kinds: List[ArgKind],
-                                  arg_names: Optional[Sequence[Optional[str]]]) -> bool:
+                                  arg_names: Optional[Sequence[Optional[str]]],
+                                  *,
+                                  self_contains_any: bool = False) -> bool:
     """May an argument containing 'Any' cause ambiguous result type on call to overloaded function?
 
     Note that this sometimes returns True even if there is no ambiguity, since a correct
@@ -4440,7 +4445,7 @@ def any_causes_overload_ambiguity(items: List[CallableType],
             if not all_same_types(matching_formals) and not all_same_types(matching_returns):
                 # Any maps to multiple different types, and the return types of these items differ.
                 return True
-    return False
+    return self_contains_any
 
 
 def all_same_types(types: List[Type]) -> bool:

test-data/unit/check-overloading.test

@@ -5335,7 +5335,68 @@ def register(cls: Type[_T]) -> int: ...
 def register(cls: Callable[..., _T]) -> str: ...
 def register(cls: Any) -> Any: return None
 
-
 x = register(Foo)
 reveal_type(x)  # N: Revealed type is "builtins.int"
 [builtins fixtures/dict.pyi]
+
+[case testOverloadSelfArgWithMultipleMatches]
+# https://github.com/python/mypy/issues/11347
+from typing import Generic, TypeVar, overload, Any
+
+T = TypeVar('T')
+
+class Some(Generic[T]):
+    @overload
+    def method(self: Some[int]) -> str: ...
+    @overload
+    def method(self: Some[str]) -> float: ...
+    def method(self): ...
+
+s1: Some[int]
+s2: Some[str]
+s3: Some[Any]
+reveal_type(s1.method())  # N: Revealed type is "builtins.str"
+reveal_type(s2.method())  # N: Revealed type is "builtins.float"
+reveal_type(s3.method()) # N: Revealed type is "Any"
+[builtins fixtures/dict.pyi]
+
+[case testOverloadSelfArgWithOtherSameArgAndMultipleMatches]
+from typing import Generic, TypeVar, overload, Any
+
+T = TypeVar('T')
+
+class Some(Generic[T]):
+    @overload
+    def method(self: Some[int], other: int) -> str: ...
+    @overload
+    def method(self: Some[str], other: int) -> float: ...
+    def method(self): ...
+
+# was ok
+s1: Some[int]
+s2: Some[str]
+s3: Some[Any]
+reveal_type(s1.method(1))  # N: Revealed type is "builtins.str"
+reveal_type(s2.method(1))  # N: Revealed type is "builtins.float"
+reveal_type(s3.method(1)) # N: Revealed type is "Any"
+[builtins fixtures/dict.pyi]
+
+[case testOverloadSelfArgWithOtherDifferentArgAndMultipleMatches]
+from typing import Generic, TypeVar, overload, Any
+
+T = TypeVar('T')
+
+class Some(Generic[T]):
+    @overload
+    def method(self: Some[int], other: int) -> str: ...
+    @overload
+    def method(self: Some[str], other: str) -> float: ...
+    def method(self): ...
+
+s1: Some[int]
+s2: Some[str]
+s3: Some[Any]
+reveal_type(s1.method(1))  # N: Revealed type is "builtins.str"
+reveal_type(s2.method('a'))  # N: Revealed type is "builtins.float"
+reveal_type(s3.method(1)) # N: Revealed type is "builtins.str"
+[builtins fixtures/dict.pyi]