From: Eric Blake <eblake@redhat.com>
Date: Sat, 30 Apr 2011 21:40:00 +0000 (-0600)
Subject: fclose: don't fail on non-seekable input stream
X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=096d7e1c450cff94143fd0681439ab42a3a63079;p=pspp

fclose: don't fail on non-seekable input stream

On mingw, for a project that uses both sockets and streams,
then fclose(stdin) when getting input from a terminal or pipe
was spuriously failing.

* modules/fclose (Depends-on): Add freading, fflush, fseeko.
* lib/fclose.c (rpl_fclose): Skip fflush for non-seekable input,
since fflush is allowed to fail in that case.

Signed-off-by: Eric Blake <eblake@redhat.com>
---

diff --git a/ChangeLog b/ChangeLog
index eb233f6061..3b5331c632 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2011-04-30  Eric Blake  <eblake@redhat.com>
+
+	fclose: don't fail on non-seekable input stream
+	* modules/fclose (Depends-on): Add freading, fflush, fseeko.
+	* lib/fclose.c (rpl_fclose): Skip fflush for non-seekable input,
+	since fflush is allowed to fail in that case.
+
 2011-04-30  Bruno Haible  <bruno@clisp.org>
 
 	dup3: cleanup
diff --git a/lib/fclose.c b/lib/fclose.c
index 1d7e85b668..bce409c960 100644
--- a/lib/fclose.c
+++ b/lib/fclose.c
@@ -22,6 +22,8 @@
 #include <errno.h>
 #include <unistd.h>
 
+#include "freading.h"
+
 /* Override fclose() to call the overridden close().  */
 
 int
@@ -30,7 +32,9 @@ rpl_fclose (FILE *fp)
 {
   int saved_errno = 0;
 
-  if (fflush (fp))
+  /* We only need to flush the file if it is not reading or if it is
+     seekable.  */
+  if ((!freading (fp) || fseeko (fp, 0, SEEK_CUR) == 0) && fflush (fp))
     saved_errno = errno;
 
   if (close (fileno (fp)) < 0 && saved_errno == 0)
diff --git a/modules/fclose b/modules/fclose
index 4f6f786910..d8727c3075 100644
--- a/modules/fclose
+++ b/modules/fclose
@@ -8,6 +8,9 @@ m4/fclose.m4
 Depends-on:
 stdio
 close
+fflush
+freading
+fseeko
 
 configure.ac:
 gl_FUNC_FCLOSE