Libc-997.1.1.tar.gz

[apple/libc.git] / stdio / FreeBSD / fflush.c

diff --git a/stdio/FreeBSD/fflush.c b/stdio/FreeBSD/fflush.c
index 573241013238279ecd98a061f7b5023a146cb8a0..5db1a1c61fd4636c32eb1e736f92ab1f1a3ba2e3 100644 (file)
--- a/stdio/FreeBSD/fflush.c
+++ b/stdio/FreeBSD/fflush.c
@@ -13,10 +13,6 @@
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
- * 3. All advertising materials mentioning features or use of this software
- *    must display the following acknowledgement:
- *     This product includes software developed by the University of
- *     California, Berkeley and its contributors.
  * 4. Neither the name of the University nor the names of its contributors
  *    may be used to endorse or promote products derived from this software
  *    without specific prior written permission.
@@ -38,11 +34,12 @@
 static char sccsid[] = "@(#)fflush.c   8.1 (Berkeley) 6/4/93";
 #endif /* LIBC_SCCS and not lint */
 #include <sys/cdefs.h>
-__FBSDID("$FreeBSD: src/lib/libc/stdio/fflush.c,v 1.12 2002/03/22 21:53:04 obrien Exp $");
+__FBSDID("$FreeBSD: src/lib/libc/stdio/fflush.c,v 1.14 2007/01/09 00:28:06 imp Exp $");
 
 #include "namespace.h"
 #include <errno.h>
 #include <stdio.h>
+#include <string.h>
 #include "un-namespace.h"
 #include "libc_private.h"
 #include "local.h"
@@ -61,9 +58,27 @@ fflush(FILE *fp)
        if (fp == NULL)
                return (_fwalk(sflush_locked));
        FLOCKFILE(fp);
+
+       /*
+        * 11103146: Conformance change:
+        * --- Begin History ---
+        * There is disagreement about the correct behaviour of fflush()
+        * when passed a file which is not open for writing.  According to
+        * the ISO C standard, the behaviour is undefined.
+        * Under linux, such an fflush returns success and has no effect;
+        * under Windows, such an fflush is documented as behaving instead
+        * as fpurge().
+        * Given that applications may be written with the expectation of
+        * either of these two behaviours, the only safe (non-astonishing)
+        * option is to return EBADF and ask that applications be fixed.
+        * --- End History ---
+        * SUSv3 now requires that fflush() returns success on a read-only
+        * stream.  In addition, the conformance tests will warn if a fflush
+        * on a read-only stream does not set the file descriptor's file offset
+        * to the real position.  We won't be fixing the warning at this time.
+        */
        if ((fp->_flags & (__SWR | __SRW)) == 0) {
-               errno = EBADF;
-               retval = EOF;
+               retval = 0;
        } else
                retval = __sflush(fp);
        FUNLOCKFILE(fp);
@@ -82,8 +97,7 @@ __fflush(FILE *fp)
        if (fp == NULL)
                return (_fwalk(sflush_locked));
        if ((fp->_flags & (__SWR | __SRW)) == 0) {
-               errno = EBADF;
-               retval = EOF;
+               retval = 0;
        } else
                retval = __sflush(fp);
        return (retval);
@@ -114,6 +128,14 @@ __sflush(FILE *fp)
        for (; n > 0; n -= t, p += t) {
                t = _swrite(fp, (char *)p, n);
                if (t <= 0) {
+                       /* 5340694: reset _p and _w on EAGAIN */
+                       if (t < 0 && errno == EAGAIN) {
+                               if (p > fp->_p) /* some was written */
+                                       memmove(fp->_p, p, n);
+                               fp->_p += n;
+                               if (!(fp->_flags & (__SLBF|__SNBF)))
+                                       fp->_w -= n;
+                       }
                        fp->_flags |= __SERR;
                        return (EOF);
                }