1 files changed, 5 insertions, 1 deletions
diff --git a/convert.c b/convert.c
index 1ec91a370e..4951372db8 100644
--- a/convert.c
+++ b/convert.c
@@ -838,7 +838,11 @@ static int null_filter_fn(struct stream_filter *filter,
 			  const char *input, size_t *isize_p,
 			  char *output, size_t *osize_p)
 {
-	size_t count = *isize_p;
+	size_t count;
+
+	if (!input)
+		return 0; /* we do not keep any states */
+	count = *isize_p;
 	if (*osize_p < count)
 		count = *osize_p;
 	if (count) {