imap-send: be more careful when casting to `curl_off_t`

When casting a `size_t` to `curl_off_t`, there is a currently uncommon
chance that the value can be cut off (`curl_off_t` is expected to be a
signed 64-bit data type).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/imap-send.c b/imap-send.c
index 2e812f5a6e9e10d187507fa4458606bd5867680a..29dc86ff272ccc0dac2d032cc4c05b7f93557fbf 100644 (file)
--- a/imap-send.c
+++ b/imap-send.c
@@ -1475,7 +1475,7 @@ static int curl_append_msgs_to_imap(struct imap_server_conf *server,
                lf_to_crlf(&msgbuf.buf);
 
                curl_easy_setopt(curl, CURLOPT_INFILESIZE_LARGE,
-                                (curl_off_t)(msgbuf.buf.len-prev_len));
+                                cast_size_t_to_curl_off_t(msgbuf.buf.len-prev_len));
 
                res = curl_easy_perform(curl);