imap: Fixed calculation of transfer when partial FETCH received

The transfer size would be calculated incorrectly if the email contained
within the FETCH response, had been partially received by the pingpong
layer. As such the following, example output, would be seen if the
amount remaining was smaller than the amount received:

* Excess found in a non pipelined read: excess = 1394, size = 262,
  maxdownload = 262, bytecount = 1374
* transfer closed with -1112 bytes remaining to read

Bug: http://curl.haxx.se/mail/lib-2013-08/0170.html
Reported-by: John Dunn

diff --git a/lib/imap.c b/lib/imap.c
index 2207087..17e9eb0 100644 (file)
--- a/lib/imap.c
+++ b/lib/imap.c
@@ -1465,10 +1465,10 @@ static CURLcode imap_state_fetch_resp(struct connectdata *conn, int imapcode,
         return result;
 
       data->req.bytecount += chunk;
-      size -= chunk;
 
       infof(data, "Written %" FORMAT_OFF_TU " bytes, %" FORMAT_OFF_TU
-            " bytes are left for transfer\n", (curl_off_t)chunk, size);
+            " bytes are left for transfer\n", (curl_off_t)chunk,
+            size - chunk);
 
       /* Have we used the entire cache or just part of it?*/
       if(pp->cache_size > chunk) {
@@ -1485,7 +1485,7 @@ static CURLcode imap_state_fetch_resp(struct connectdata *conn, int imapcode,
       }
     }
 
-    if(!size)
+    if(data->req.bytecount == size)
       /* The entire data is already transferred! */
       Curl_setup_transfer(conn, -1, -1, FALSE, NULL, -1, NULL);
     else {