1 files changed, 19 insertions, 0 deletions
diff --git a/Lib/asyncio/protocols.py b/Lib/asyncio/protocols.py
index b8d2e6be55..4d47da387c 100644
--- a/Lib/asyncio/protocols.py
+++ b/Lib/asyncio/protocols.py
@@ -189,3 +189,22 @@ class SubprocessProtocol(BaseProtocol):
 
     def process_exited(self):
         """Called when subprocess has exited."""
+
+
+def _feed_data_to_bufferred_proto(proto, data):
+    data_len = len(data)
+    while data_len:
+        buf = proto.get_buffer(data_len)
+        buf_len = len(buf)
+        if not buf_len:
+            raise RuntimeError('get_buffer() returned an empty buffer')
+
+        if buf_len >= data_len:
+            buf[:data_len] = data
+            proto.buffer_updated(data_len)
+            return
+        else:
+            buf[:buf_len] = data[:buf_len]
+            proto.buffer_updated(buf_len)
+            data = data[buf_len:]
+            data_len = len(data)