From: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Date: Sat, 25 Jun 2011 02:13:11 +0000 (+1000)
Subject: handle the case where we try a multi-read that is completely beyond the end of file.
X-Git-Tag: upstream/1.9.6^2~388
X-Git-Url: https://git.piment-noir.org/?a=commitdiff_plain;h=215228a23de45d62bb5154e919d23da2b435880b;p=deb_libnfs.git

handle the case where we try a multi-read that is completely beyond the end of file.

when a multi-read was completely beyond the end of file, this caused us to invoke the callback with a 'read-count' of <0  which the callback would treat as a failure.
This would then cause the callback to treat the data pointer as an error string and try to use it for nfs_set_error().
Since the data pointer was actually a real binary databuffer and not an error string this would cause the NFS error string to look like it contained garbage data.

In this case, where the multi-read fails to read any data at all since it if fully beyond end of file,  make sure to invoke the callback with a read-count of 0
---

diff --git a/lib/libnfs.c b/lib/libnfs.c
index 996b988..d1f4f0e 100644
--- a/lib/libnfs.c
+++ b/lib/libnfs.c
@@ -889,7 +889,11 @@ static void nfs_pread_mcb(struct rpc_context *rpc _U_, int status, void *command
 	}
 
 	data->nfsfh->offset = data->max_offset;
-	data->cb(data->max_offset - data->start_offset, nfs, data->buffer, data->private_data);
+	if (data->max_offset - data->start_offset >= 0) {
+		data->cb(data->max_offset - data->start_offset, nfs, data->buffer, data->private_data);
+	} else {
+		data->cb(0, nfs, data->buffer, data->private_data);
+	}
 	free_nfs_cb_data(data);
 	free(mdata);
 }