X-Git-Url: https://git.saurik.com/apple/libc.git/blobdiff_plain/3d9156a7a519a5e3aa1b92e9d9d4b991f1aed7ff..aa54d2fad3d9038b43475aa93c76795c5141a993:/stdio/FreeBSD/fflush.c?ds=sidebyside

diff --git a/stdio/FreeBSD/fflush.c b/stdio/FreeBSD/fflush.c
index 59da908..db6761d 100644
--- 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 1.13 2004/07/04 20:17:00 cperciva 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"
@@ -56,28 +53,14 @@ static int	sflush_locked(FILE *);
 int
 fflush(FILE *fp)
 {
-	int retval;
+	int retval = 0;
 
-	if (fp == NULL)
+	if (fp == NULL) {
 		return (_fwalk(sflush_locked));
-	FLOCKFILE(fp);
+	}
 
-	/*
-	 * There is disagreement about the correct behaviour of fflush()
-	 * when passed a file which is not open for reading.  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.
-	 */
-	if ((fp->_flags & (__SWR | __SRW)) == 0) {
-		errno = EBADF;
-		retval = EOF;
-	} else
-		retval = __sflush(fp);
+	FLOCKFILE(fp);
+	retval = __sflush(fp);
 	FUNLOCKFILE(fp);
 	return (retval);
 }
@@ -94,8 +77,7 @@ __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);
@@ -108,26 +90,77 @@ __sflush(FILE *fp)
 	int n, t;
 
 	t = fp->_flags;
-	if ((t & __SWR) == 0)
-		return (0);
 
 	if ((p = fp->_bf._base) == NULL)
 		return (0);
 
-	n = fp->_p - p;		/* write this much */
-
 	/*
-	 * Set these immediately to avoid problems with longjmp and to allow
-	 * exchange buffering (via setvbuf) in user write function.
+	 * SUSv3 requires that fflush() on a seekable input stream updates the file
+	 * position indicator with the underlying seek function.  Use a dumb fseek
+	 * for this (don't attempt to preserve the buffers).
 	 */
-	fp->_p = p;
-	fp->_w = t & (__SLBF|__SNBF) ? 0 : fp->_bf._size;
-
-	for (; n > 0; n -= t, p += t) {
-		t = _swrite(fp, (char *)p, n);
-		if (t <= 0) {
-			fp->_flags |= __SERR;
-			return (EOF);
+	if ((t & __SRD) != 0) {
+		if (fp->_seek == NULL) {
+			/*
+			 * No way to seek this file -- just return "success."
+			 */
+			return (0);
+		}
+
+		n = fp->_r;
+
+		if (n > 0) {
+			/*
+			 * See _fseeko's dumb path.
+			 */
+			if (_sseek(fp, (fpos_t)-n, SEEK_CUR) == -1) {
+				if (errno == ESPIPE) {
+					/*
+					 * Ignore ESPIPE errors, since there's no way to put the bytes
+					 * back into the pipe.
+					 */
+					return (0);
+				}
+				return (EOF);
+			}
+
+			if (HASUB(fp)) {
+				FREEUB(fp);
+			}
+			fp->_p = fp->_bf._base;
+			fp->_r = 0;
+			fp->_flags &= ~__SEOF;
+			memset(&fp->_mbstate, 0, sizeof(mbstate_t));
+		}
+		return (0);
+	}
+
+	if ((t & __SWR) != 0) {
+		n = fp->_p - p;		/* write this much */
+
+		/*
+		 * Set these immediately to avoid problems with longjmp and to allow
+		 * exchange buffering (via setvbuf) in user write function.
+		 */
+		fp->_p = p;
+		fp->_w = t & (__SLBF|__SNBF) ? 0 : fp->_bf._size;
+
+		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);
+			}
 		}
 	}
 	return (0);