From 576ace1f2f977342b837d2da3a23c5c9b0f61af1 Mon Sep 17 00:00:00 2001
From: Takashi Yano <takashi.yano@nifty.ne.jp>
Date: Thu, 11 Nov 2021 12:30:24 +0900
Subject: [PATCH] Cygwin: pipe: Fix raw_write() for non-cygwin pipe with size
 zero.

- Currently, raw_write() fails to handle size zero pipe which may
  be created by non-cygwin apps (e.g. Windows native ninja). This
  patch fixes the issue.

Addresses:
  https://cygwin.com/pipermail/cygwin/2021-November/249844.html
---
 winsup/cygwin/fhandler_pipe.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/winsup/cygwin/fhandler_pipe.cc b/winsup/cygwin/fhandler_pipe.cc
index 13731437e..9392a28c1 100644
--- a/winsup/cygwin/fhandler_pipe.cc
+++ b/winsup/cygwin/fhandler_pipe.cc
@@ -449,7 +449,7 @@ fhandler_pipe_fifo::raw_write (const void *ptr, size_t len)
       return -1;
     }
 
-  if (len <= pipe_buf_size)
+  if (len <= pipe_buf_size || pipe_buf_size == 0)
     chunk = len;
   else if (is_nonblocking ())
     chunk = len = pipe_buf_size;
-- 
2.43.5