From: Eli Zaretskii <eliz@gnu.org>
Date: Wed, 21 Dec 2022 19:23:51 +0000 (+0200)
Subject: Fix write-region to null device on MS-Windows
X-Git-Tag: emacs-29.0.90~1053
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=ec9fbad908d;p=emacs.git

Fix write-region to null device on MS-Windows

* src/fileio.c (write_region) [WINDOWSNT]: Ignore EBADF errors
from fsync -- this means fsync is not supported for this file.
Happens, for example, with the null device.  (Bug#59545)
---

diff --git a/src/fileio.c b/src/fileio.c
index 835c42cc0a4..31353be5d5a 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -5387,12 +5387,16 @@ write_region (Lisp_Object start, Lisp_Object end, Lisp_Object filename,
     {
       /* Transfer data and metadata to disk, retrying if interrupted.
 	 fsync can report a write failure here, e.g., due to disk full
-	 under NFS.  But ignore EINVAL, which means fsync is not
-	 supported on this file.  */
+	 under NFS.  But ignore EINVAL (and EBADF on Windows), which
+	 means fsync is not supported on this file.  */
       while (fsync (desc) != 0)
 	if (errno != EINTR)
 	  {
-	    if (errno != EINVAL)
+	    if (errno != EINVAL
+#ifdef WINDOWSNT
+		&& errno != EBADF
+#endif
+		)
 	      ok = 0, save_errno = errno;
 	    break;
 	  }