From 5f0ae7a0626cbe70944c67065292cbb056d0a7c9 Mon Sep 17 00:00:00 2001
From: Daniel Stenberg <daniel@haxx.se>
Date: Thu, 30 Sep 2010 23:08:37 +0200
Subject: [PATCH] SFTP: avoid downloading negative sizes!

It is still not clarified exactly why this happens, but libssh2
sometimes report a negative file size for the remote SFTP file and that
deeply confuses libcurl (or crashes it) so this precaution is added to
avoid badness.

Reported by: Ernest Beinrohr
Bug: http://curl.haxx.se/bug/view.cgi?id=3076430
---
 lib/ssh.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/lib/ssh.c b/lib/ssh.c
index 06fd43999..026212103 100644
--- a/lib/ssh.c
+++ b/lib/ssh.c
@@ -1911,9 +1911,12 @@ static CURLcode ssh_statemach_act(struct connectdata *conn, bool *block)
         data->req.maxdownload = -1;
       }
       else {
-        curl_off_t size;
+        curl_off_t size = attrs.filesize;
 
-        size = attrs.filesize;
+        if(size < 0) {
+          failf(data, "Bad file size (%" FORMAT_OFF_T ")", size);
+          return CURLE_BAD_DOWNLOAD_RESUME;
+        }
         if(conn->data->state.use_range) {
           curl_off_t from, to;
           char *ptr;