ftp: allow CURLOPT_IGNORE_CONTENT_LENGTH to ignore size

This allows FTP transfers with growing (or shrinking) files without
causing a transfer error.

Closes #480

1 files changed, 14 insertions, 2 deletions

diff --git a/lib/ftp.c b/lib/ftp.c
index 639a063ea..21db56c8e 100644
--- a/lib/ftp.c
+++ b/lib/ftp.c
@@ -1790,8 +1790,20 @@ static CURLcode ftp_state_quote(struct connectdata *conn,
           result = ftp_state_retr(conn, ftpc->known_filesize);
         }
         else {
-          PPSENDF(&ftpc->pp, "SIZE %s", ftpc->file);
-          state(conn, FTP_RETR_SIZE);
+          if(data->set.ignorecl) {
+            /* This code is to support download of growing files.  It prevents
+               the state machine from requesting the file size from the
+               server.  With an unknown file size the download continues until
+               the server terminates it, otherwise the client stops if the
+               received byte count exceeds the reported file size.  Set option
+               CURLOPT_IGNORE_CONTENT_LENGTH to 1 to enable this behavior.*/
+            PPSENDF(&ftpc->pp, "RETR %s", ftpc->file);
+            state(conn, FTP_RETR);
+          }
+          else {
+            PPSENDF(&ftpc->pp, "SIZE %s", ftpc->file);
+            state(conn, FTP_RETR_SIZE);
+          }
         }
       }
       break;