(prepend_default_options): Don't use NULL, for portability.

[chaz/tar] / lib / full-write.c

diff --git a/lib/full-write.c b/lib/full-write.c
index 062f2b2c6cb7ea2e1b93dbe26434cb04db7e5d2c..f4c14e8062c3d3615d6d787a32f8f32662f5d229 100644 (file)
--- a/lib/full-write.c
+++ b/lib/full-write.c
@@ -1,5 +1,5 @@
 /* full-write.c -- an interface to write that retries after interrupts
-   Copyright (C) 1993, 1994, 1997, 1998, 1999 Free Software Foundation, Inc.
+   Copyright 1993, 1994, 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -24,6 +24,8 @@
 
 #include <sys/types.h>
 
+#include "safe-read.h"
+
 #if HAVE_UNISTD_H
 # include <unistd.h>
 #endif
@@ -34,7 +36,7 @@ extern int errno;
 #endif
 
 /* Write LEN bytes at PTR to descriptor DESC, retrying if interrupted.
-   Return LEN upon success, write's (negative) error code otherwise.  */
+   Return LEN upon success, -1 (setting errno) otherwise.  */
 
 ssize_t
 full_write (int desc, const char *ptr, size_t len)
@@ -44,17 +46,16 @@ full_write (int desc, const char *ptr, size_t len)
   while (len > 0)
     {
       ssize_t written = write (desc, ptr, len);
-      /* FIXME: write on my slackware Linux 1.2.13 returns zero when
-        I try to write more data than there is room on a floppy disk.
-        This puts dd into an infinite loop.  Reproduce with
-        dd if=/dev/zero of=/dev/fd0.  */
-      if (written < 0)
+      if (written <= 0)
        {
+         /* Some buggy drivers return 0 when you fall off a device's end.  */
+         if (written == 0)
+           errno = ENOSPC;
 #ifdef EINTR
          if (errno == EINTR)
            continue;
 #endif
-         return written;
+         return -1;
        }
       total_written += written;
       ptr += written;