patch 8.1.0889: MS-Windows: a channel write may hang commit https://github.com/vim/vim/commit/6524068ff3252f1373807f1ebfde21408cef624e Author: Bram Moolenaar <Bram@vim.org> Date: Sun Feb 10 22:23:26 2019 +0100 patch 8.1.0889: MS-Windows: a channel write may hang Problem: MS-Windows: a channel write may hang. Solution: Check for WriteFile() not writing anything. (Yasuhiro Matsumoto, closes #3920)

--- a/src/testdir/test_channel_pipe.py
+++ b/src/testdir/test_channel_pipe.py
@@ -18,6 +18,9 @@ if __name__ == "__main__":
             print(sys.argv[1], end='')
             sys.stdout.flush()
             sys.exit(0)
+        elif sys.argv[1].startswith("busy"):
+            time.sleep(100)
+            sys.exit(0)
         else:
             print(sys.argv[1])
             sys.stdout.flush()