From bacfdfd11bb29a640c6244e8c3f75b61f6a36088 Mon Sep 17 00:00:00 2001
From: Andrew Svetlov <andrew.svetlov@gmail.com>
Date: Tue, 5 Dec 2017 10:36:33 +0200
Subject: [PATCH 1/2] Make multipart.boundary a str property

---
 aiohttp/multipart.py         | 4 ++--
 docs/multipart_reference.rst | 6 +++++-
 tests/test_multipart.py      | 2 +-
 3 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/aiohttp/multipart.py b/aiohttp/multipart.py
index fc38725a9a3..f41ae726dbf 100644
--- a/aiohttp/multipart.py
+++ b/aiohttp/multipart.py
@@ -686,7 +686,7 @@ def _boundary_value(self):
         #                  / DIGIT / ALPHA
         #                  ; any VCHAR, except delimiters
         # VCHAR           = %x21-7E
-        value = self.boundary
+        value = self._boundary
         if re.match(self._valid_tchar_regex, value):
             return value.decode('ascii')  # cannot fail
 
@@ -701,7 +701,7 @@ def _boundary_value(self):
 
     @property
     def boundary(self):
-        return self._boundary
+        return self._boundary.decode('ascii')
 
     def append(self, obj, headers=None):
         if headers is None:
diff --git a/docs/multipart_reference.rst b/docs/multipart_reference.rst
index f7c67fb9e3a..1d43e6d4822 100644
--- a/docs/multipart_reference.rst
+++ b/docs/multipart_reference.rst
@@ -165,7 +165,11 @@ Multipart reference
 
    .. attribute:: boundary
 
-      The byte-string representation of the boundary.
+      The string (:class:`str`) representation of the boundary.
+
+      .. versionchanged:: 3.0
+
+         Property type was changed from :class:`bytes` to :class:`str`.
 
    .. method:: append(obj, headers=None)
 
diff --git a/tests/test_multipart.py b/tests/test_multipart.py
index 5f4fae14da8..131d6739883 100644
--- a/tests/test_multipart.py
+++ b/tests/test_multipart.py
@@ -762,7 +762,7 @@ async def test_reading_skips_prelude(self):
 
 async def test_writer(writer):
     assert writer.size == 0
-    assert writer.boundary == b':'
+    assert writer.boundary == ':'
 
 
 async def test_writer_serialize_io_chunk(buf, stream, writer):

From 655f388c1f0f3b52bec5a1fac7a79aaa46423be6 Mon Sep 17 00:00:00 2001
From: Andrew Svetlov <andrew.svetlov@gmail.com>
Date: Tue, 5 Dec 2017 11:44:44 +0200
Subject: [PATCH 2/2] Add changenote

---
 CHANGES/2589.feature | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 CHANGES/2589.feature

diff --git a/CHANGES/2589.feature b/CHANGES/2589.feature
new file mode 100644
index 00000000000..0e835afba33
--- /dev/null
+++ b/CHANGES/2589.feature
@@ -0,0 +1 @@
+`MultipartWriter.boundary` is `str` now.