commit e49bf0f353a968cddc4d8e6ea668b9d2d116e2ac
author Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com> Sat Feb 24 09:39:18 2018 -0800
committer GitHub <noreply@github.com> Sat Feb 24 09:39:18 2018 -0800
tree 1dbc9e1dc01efec399c905691542eeb9a671c0ac
parent 46632f4d3c1f3aef875d2ada750a298ab0510992

bpo-31966: Fixed WindowsConsoleIO.write() for writing empty data. (GH-5754)

(cherry picked from commit 42c35d9c0c8175332f50fbe034a001fe52f057b9)

Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>

Modules/_io/winconsoleio.c

diff --git a/Modules/_io/winconsoleio.c b/Modules/_io/winconsoleio.c
index 30d1c76..b85c11b 100644
--- a/Modules/_io/winconsoleio.c
+++ b/Modules/_io/winconsoleio.c
@@ -964,6 +964,9 @@
     if (!self->writable)
         return err_mode("writing");
 
+    if (!b->len) {
+        return PyLong_FromLong(0);
+    }
     if (b->len > BUFMAX)
         len = BUFMAX;
     else