From 097e9f5e71844cb84bdef2d787419460a16443e3 Mon Sep 17 00:00:00 2001
From: David Euresti <david@euresti.com>
Date: Thu, 22 Mar 2018 10:50:07 -0700
Subject: [PATCH] Fix issue with attrib ordering. (#1980)

A call like this:

```
from attr import attrib
from attr.validators import optional, instance_of

c = attrib(default=None, validator=optional(instance_of(bytes)))
```

Was returning no return value, because the first overload was T -> T.
The solution was to change the ordering so that the first overload is
None -> T and infer the type from the other arguments.
---
 third_party/2and3/attr/__init__.pyi | 38 ++++++++++++++---------------
 1 file changed, 19 insertions(+), 19 deletions(-)

diff --git a/third_party/2and3/attr/__init__.pyi b/third_party/2and3/attr/__init__.pyi
index e4961491e..3422fc89d 100644
--- a/third_party/2and3/attr/__init__.pyi
+++ b/third_party/2and3/attr/__init__.pyi
@@ -70,7 +70,19 @@ class Attribute(Generic[_T]):
 # This makes this type of assignments possible:
 #     x: int = attr(8)
 
-# 1st form catches _T set and works around mypy issue #4554
+# This form catches an explicit None or no default and infers the type from the other arguments.
+@overload
+def attrib(default: None = ...,
+           validator: Optional[_ValidatorArgType[_T]] = ...,
+           repr: bool = ...,
+           cmp: bool = ...,
+           hash: Optional[bool] = ...,
+           init: bool = ...,
+           convert: Optional[_ConverterType[_T]] = ...,
+           metadata: Optional[Mapping[Any, Any]] = ...,
+           type: Optional[Type[_T]] = ...,
+           converter: Optional[_ConverterType[_T]] = ...) -> _T: ...
+# This form catches an explicit default argument.
 @overload
 def attrib(default: _T,
            validator: Optional[_ValidatorArgType[_T]] = ...,
@@ -82,19 +94,7 @@ def attrib(default: _T,
            metadata: Optional[Mapping[Any, Any]] = ...,
            type: Optional[Type[_T]] = ...,
            converter: Optional[_ConverterType[_T]] = ...) -> _T: ...
-# 2nd one with an optional default.
-@overload
-def attrib(default: Optional[_T] = ...,
-           validator: Optional[_ValidatorArgType[_T]] = ...,
-           repr: bool = ...,
-           cmp: bool = ...,
-           hash: Optional[bool] = ...,
-           init: bool = ...,
-           convert: Optional[_ConverterType[_T]] = ...,
-           metadata: Optional[Mapping[Any, Any]] = ...,
-           type: Optional[Type[_T]] = ...,
-           converter: Optional[_ConverterType[_T]] = ...) -> _T: ...
-# 3rd form no _T , so returns Any.
+# This form catches explicit None or no default but with no other arguments returns Any.
 @overload
 def attrib(default: None = ...,
            validator: None = ...,
@@ -106,7 +106,7 @@ def attrib(default: None = ...,
            metadata: Optional[Mapping[Any, Any]] = ...,
            type: None = ...,
            converter: None = ...) -> Any: ...
-# 4th form covers type=non-Type: e.g. forward references (str), Any
+# This form covers type=non-Type: e.g. forward references (str), Any
 @overload
 def attrib(default: Optional[_T] = ...,
            validator: Optional[_ValidatorArgType[_T]] = ...,
@@ -208,7 +208,7 @@ def get_run_validators() -> bool: ...
 
 
 @overload
-def ib(default: _T,
+def ib(default: None = ...,
        validator: Optional[_ValidatorArgType[_T]] = ...,
        repr: bool = ...,
        cmp: bool = ...,
@@ -219,7 +219,7 @@ def ib(default: _T,
        type: Optional[Type[_T]] = ...,
        converter: Optional[_ConverterType[_T]] = ...) -> _T: ...
 @overload
-def ib(default: Optional[_T] = ...,
+def ib(default: _T,
        validator: Optional[_ValidatorArgType[_T]] = ...,
        repr: bool = ...,
        cmp: bool = ...,
@@ -253,7 +253,7 @@ def ib(default: Optional[_T] = ...,
        converter: Optional[_ConverterType[_T]] = ...) -> Any: ...
 
 @overload
-def attr(default: _T,
+def attr(default: None = ...,
          validator: Optional[_ValidatorArgType[_T]] = ...,
          repr: bool = ...,
          cmp: bool = ...,
@@ -264,7 +264,7 @@ def attr(default: _T,
          type: Optional[Type[_T]] = ...,
          converter: Optional[_ConverterType[_T]] = ...) -> _T: ...
 @overload
-def attr(default: Optional[_T] = ...,
+def attr(default: _T,
          validator: Optional[_ValidatorArgType[_T]] = ...,
          repr: bool = ...,
          cmp: bool = ...,