[master] b8ee9ea Make this assert even more precise.

[Poul-Henning Kamp]

commit b8ee9ea7aa2f9bfe2a341558e1b85efe9de14868
Author: Poul-Henning Kamp <phk at FreeBSD.org>
Date:   Wed Mar 11 09:31:32 2015 +0000

    Make this assert even more precise.

diff --git a/bin/varnishd/http1/cache_http1_vfp.c b/bin/varnishd/http1/cache_http1_vfp.c
index 90ac22e..99d87da 100644
--- a/bin/varnishd/http1/cache_http1_vfp.c
+++ b/bin/varnishd/http1/cache_http1_vfp.c
@@ -55,7 +55,7 @@ v1f_read(const struct vfp_ctx *vc, struct http_conn *htc, void *d, ssize_t len)
 
 	CHECK_OBJ_NOTNULL(vc, VFP_CTX_MAGIC);
 	CHECK_OBJ_NOTNULL(htc, HTTP_CONN_MAGIC);
-	assert(len >= 0);
+	assert(len > 0);
 	l = 0;
 	p = d;
 	if (htc->pipeline_b) {