Use a better buffer size in emacs_perror

* src/sysdep.c (emacs_perror): Since the buffer is for avoiding
interleaving, size it via PIPE_BUF not BUFSIZ.
* src/sysstdio.h (PIPE_BUF): Provide a default.

1 files changed, 5 insertions, 0 deletions

diff --git a/src/sysstdio.h b/src/sysstdio.h
index 5303e8a15b2..637f5fdfa6d 100644
--- a/src/sysstdio.h
+++ b/src/sysstdio.h
@@ -21,6 +21,7 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 #define EMACS_SYSSTDIO_H
 
 #include <fcntl.h>
+#include <limits.h>
 #include <stdio.h>
 #include "unlocked-io.h"
 
@@ -38,4 +39,8 @@ extern void close_output_streams (void);
 # define FOPEN_TEXT ""
 #endif
 
+#ifndef PIPE_BUF
+ #define PIPE_BUF MAX_ALLOCA
+#endif
+
 #endif /* EMACS_SYSSTDIO_H */