Override gnulib's fflush.c on DragonFly with a far less intrusive

versions. This is still in discussion with upstream, but working m4
is critical, so apply this stop-gap solution. It works on the other
BSD derived stdio implementations as well, if you want to switch.

1 files changed, 72 insertions, 0 deletions

diff --git a/devel/m4/files/bsd-fflush.c b/devel/m4/files/bsd-fflush.c
new file mode 100644
index 00000000000..f0bdf4ea09c
--- /dev/null
+++ b/devel/m4/files/bsd-fflush.c
@@ -0,0 +1,72 @@
+/* $NetBSD: bsd-fflush.c,v 1.1 2007/07/29 14:36:46 joerg Exp $ */
+
+/*-
+ * Copyright (c) 2007 Joerg Sonnenberger <joerg@NetBSD.org>.
+ * All rights reserved.
+ *
+ * This code was developed as part of Google's Summer of Code 2007 program.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
+ * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+ 
+#include <errno.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#undef fflush
+
+int
+rpl_fflush(FILE *fp)
+{
+#if defined(__DragonFly__)
+	struct __FILE_public *fp_ = (struct __FILE_public *)fp;
+#else
+#define	fp_ fp
+#endif
+	off_t pos;
+
+	/* NULL pointer or writeable stream: use normal fflush. */
+	if (fp == NULL || (fp_->_flags & (__SWR | __SRW)) != 0)
+		return fflush(fp);
+
+	/* Get current position, possibly different from file pointer. */
+	pos = ftello(fp);
+	if (pos == -1) {
+		errno = EBADF;
+		return -1;
+	}
+	/* Purge buffers. */
+	if (fpurge(fp) == EOF)
+		return -1;
+
+	/*
+	 * Disable seek optimisation.  This is forces the following
+	 * fseeko to seek the actual position and not realign
+	 * the file pointer on a block boundary.
+	 */
+	fp_->_flags |= __SNPT;
+
+	return fseeko(fp, pos, SEEK_SET);
+}