Bug fix: A final fsync(2) was performed with stdio drives, even if not desired

cdrskin/cdrskin_timestamp.h

@@ -1 +1 @@
-#define Cdrskin_timestamP "2014.04.06.111004"
+#define Cdrskin_timestamP "2014.04.07.180808"

libburn/libburn.h

@@ -3225,7 +3225,10 @@ void burn_write_opts_set_obs_pad(struct burn_write_opts *opts, int pad);
     from being clogged with lots of pending data for slow devices.
     @param opts   The write opts to change
     @param rythm  Number of 2KB output blocks after which fsync(2) is
-                  performed. -1 means no fsync(), 0 means default,
+                  performed.
+                  -1 means no fsync()
+                   0 means default
+                   1 means fsync() only at end, @since 1.3.8 (noop before 1.3.8)
                   elsewise the value must be >= 32.
                   Default is currently 8192 = 16 MB.
     @since 0.7.4

libburn/options.c

@@ -522,9 +522,11 @@ void burn_write_opts_set_obs_pad(struct burn_write_opts *opts, int pad)
 void burn_write_opts_set_stdio_fsync(struct burn_write_opts *opts, int rythm)
 {
 	if (rythm == -1)
-		opts->stdio_fsync_size = 0;
+		opts->stdio_fsync_size = -1; /* never */
 	else if (rythm == 0)
 		opts->stdio_fsync_size = Libburn_stdio_fsync_limiT;
+	else if (rythm == 1)
+		opts->stdio_fsync_size = 0; /* only at end of writing */
 	else if (rythm >= 32)
 		opts->stdio_fsync_size = rythm;
 }

libburn/write.c

@@ -2665,7 +2665,7 @@ int burn_stdio_mmc_dummy_write(struct burn_drive *d, int start,
 */
 int burn_stdio_sync_cache(int fd, struct burn_drive *d, int flag)
 {
-	int ret;
+	int ret, do_fsync;
 	char *msg = NULL;
 
 	if (fd < 0) {
@@ -2678,11 +2678,18 @@ int burn_stdio_sync_cache(int fd, struct burn_drive *d, int flag)
 		return 0;
 	}
 	d->needs_sync_cache = 0;
-	if (!(flag & 1))
-		libdax_msgs_submit(libdax_messenger, -1, 0x00000002,
-			   LIBDAX_MSGS_SEV_DEBUG, LIBDAX_MSGS_PRIO_ZERO,
-			   "syncing cache (stdio fsync)", 0, 0);
-	ret = fsync(fd);
+	do_fsync = 0;
+	if (d->write_opts != NULL)
+		do_fsync = (d->write_opts->stdio_fsync_size >= 0);
+	if (do_fsync) {
+		if (!(flag & 1))
+			libdax_msgs_submit(libdax_messenger, -1, 0x00000002,
+				LIBDAX_MSGS_SEV_DEBUG, LIBDAX_MSGS_PRIO_ZERO,
+				"syncing cache (stdio fsync)", 0, 0);
+		ret = fsync(fd);
+	} else {
+		ret = 0;
+	}
 	if (ret != 0 && errno == EIO) {
 		BURN_ALLOC_MEM(msg, char, 160);