tests: Fix read past buffer.

* tests/t-poll.c (test_poll): Fix read past buffer.
--
Found using gcc and AddressSanitizer.

Signed-off-by: Justus Winter <justus@g10code.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/tests/t-poll.c b/tests/t-poll.c
index 5955d50..57cdb75 100644
--- a/tests/t-poll.c
+++ b/tests/t-poll.c
@@ -288,7 +288,9 @@ test_poll (void)
               if (!ret)
                 {
                   assert (nwritten <= used);
-                  memmove (buffer, buffer + nwritten, nwritten);
+                  /* Move the remaining data to the front of buffer.  */
+                  memmove (buffer, buffer + nwritten,
+                           sizeof buffer - nwritten);
                   used -= nwritten;
                 }
               ret = es_fflush (fds[1].stream);