Fix abstract and non-abstract variant error for prop.deleter (#15395)

Author: hauntsaninja

mypy/semanal.py

@@ -1337,6 +1337,8 @@ def analyze_property_with_multi_part_definition(self, defn: OverloadedFuncDef) -
                             first_item.var.is_settable_property = True
                             # Get abstractness from the original definition.
                             item.func.abstract_status = first_item.func.abstract_status
+                        if node.name == "deleter":
+                            item.func.abstract_status = first_item.func.abstract_status
                     else:
                         self.fail(
                             f"Only supported top decorator is @{first_item.func.name}.setter", item

test-data/unit/check-abstract.test

@@ -735,7 +735,44 @@ class A(metaclass=ABCMeta):
     def x(self) -> int: pass
     @x.setter
     def x(self, x: int) -> None: pass
-[out]
+
+[case testReadWriteDeleteAbstractProperty]
+from abc import ABC, abstractmethod
+class Abstract(ABC):
+    @property
+    @abstractmethod
+    def prop(self) -> str: ...
+
+    @prop.setter
+    @abstractmethod
+    def prop(self, code: str) -> None: ...
+
+    @prop.deleter
+    @abstractmethod
+    def prop(self) -> None: ...
+
+class Good(Abstract):
+    @property
+    def prop(self) -> str: ...
+    @prop.setter
+    def prop(self, code: str) -> None: ...
+    @prop.deleter
+    def prop(self) -> None: ...
+
+class Bad1(Abstract):
+    @property  # E: Read-only property cannot override read-write property
+    def prop(self) -> str: ...
+
+class ThisShouldProbablyError(Abstract):
+    @property
+    def prop(self) -> str: ...
+    @prop.setter
+    def prop(self, code: str) -> None: ...
+
+a = Good()
+reveal_type(a.prop)  # N: Revealed type is "builtins.str"
+a.prop = 123  # E: Incompatible types in assignment (expression has type "int", variable has type "str")
+[builtins fixtures/property.pyi]
 
 [case testInstantiateClassWithReadOnlyAbstractProperty]
 from abc import abstractproperty, ABCMeta
@@ -767,7 +804,7 @@ b = B()
 b.x() # E: "int" not callable
 [builtins fixtures/property.pyi]
 
-[case testImplementReradWriteAbstractPropertyViaProperty]
+[case testImplementReadWriteAbstractPropertyViaProperty]
 from abc import abstractproperty, ABCMeta
 class A(metaclass=ABCMeta):
     @abstractproperty