From: Paul Eggert <eggert@cs.ucla.edu>
Date: Sun, 18 Dec 2022 19:45:06 +0000 (-0800)
Subject: Don’t hang when copying FIFOs
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=ab3cfa4a17663cf479f286149a2289974dd67240;p=emacs.git

Don’t hang when copying FIFOs

* src/fileio.c (Fcopy_file): Open the input file with O_NONBLOCK.
This prevents a hang if the input file is a FIFO.
If it’s a regular file O_NONBLOCK has no effect;
otherwise the file is soon rejected anyway.
---

diff --git a/src/fileio.c b/src/fileio.c
index 92335b639cd..a50f8d67c11 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -2219,7 +2219,7 @@ permissions.  */)
       report_file_error ("Copying permissions to", newname);
     }
 #else /* not WINDOWSNT */
-  ifd = emacs_open (SSDATA (encoded_file), O_RDONLY, 0);
+  ifd = emacs_open (SSDATA (encoded_file), O_RDONLY | O_NONBLOCK, 0);
 
   if (ifd < 0)
     report_file_error ("Opening input file", file);