bpo-42140: Improve asyncio.wait function (GH-22938)

# Improve asyncio.wait function

The original code creates the futures set two times.
We can create this set before, avoiding the second creation.

This new behaviour [breaks the aiokafka library](https://github.com/aio-libs/aiokafka/pull/672), because it gives an iterator to that function, so the second iteration become empty.

Automerge-Triggered-By: GH:1st1

1 files changed, 4 insertions, 2 deletions

diff --git a/Lib/asyncio/tasks.py b/Lib/asyncio/tasks.py
index ad31f5d..f486b67 100644
--- a/Lib/asyncio/tasks.py
+++ b/Lib/asyncio/tasks.py
@@ -400,13 +400,15 @@ async def wait(fs, *, loop=None, timeout=None, return_when=ALL_COMPLETED):
                       "and scheduled for removal in Python 3.10.",
                       DeprecationWarning, stacklevel=2)
 
-    if any(coroutines.iscoroutine(f) for f in set(fs)):
+    fs = set(fs)
+
+    if any(coroutines.iscoroutine(f) for f in fs):
         warnings.warn("The explicit passing of coroutine objects to "
                       "asyncio.wait() is deprecated since Python 3.8, and "
                       "scheduled for removal in Python 3.11.",
                       DeprecationWarning, stacklevel=2)
 
-    fs = {ensure_future(f, loop=loop) for f in set(fs)}
+    fs = {ensure_future(f, loop=loop) for f in fs}
 
     return await _wait(fs, timeout, return_when, loop)