X-Git-Url: https://git.distorted.org.uk/u/mdw/putty/blobdiff_plain/939c2b22a74142b76a62ba02b9da29ccb20dc5c2..2ac3322ef9bc032ad942753a56696764aa0b0f74:/unix/uxsftp.c

diff --git a/unix/uxsftp.c b/unix/uxsftp.c
index 7045c322..f5fc12e3 100644
--- a/unix/uxsftp.c
+++ b/unix/uxsftp.c
@@ -433,8 +433,27 @@ static int ssh_sftp_do_select(int include_stdin, int no_fds_ok)
 	    ret = select(maxfd, &rset, &wset, &xset, ptv);
 	    if (ret == 0)
 		now = next;
-	    else
-		now = GETTICKCOUNT();
+	    else {
+		long newnow = GETTICKCOUNT();
+		/*
+		 * Check to see whether the system clock has
+		 * changed massively during the select.
+		 */
+		if (newnow - now < 0 || newnow - now > next - now) {
+		    /*
+		     * If so, look at the elapsed time in the
+		     * select and use it to compute a new
+		     * tickcount_offset.
+		     */
+		    long othernow = now + tv.tv_sec * 1000 + tv.tv_usec / 1000;
+		    /* So we'd like GETTICKCOUNT to have returned othernow,
+		     * but instead it return newnow. Hence ... */
+		    tickcount_offset += othernow - newnow;
+		    now = othernow;
+		} else {
+		    now = newnow;
+		}
+	    }
 	} while (ret < 0 && errno != EINTR);
     } while (ret == 0);