[master] 7da6220df Assert

[Dridi Boukelmoune]

commit 7da6220dfd86416200c43d84d40fce0cae1b5bae
Author: Dridi Boukelmoune <dridi.boukelmoune at gmail.com>
Date:   Mon Dec 16 12:16:17 2019 +0100

    Assert

diff --git a/bin/varnishd/cache/cache_ws.c b/bin/varnishd/cache/cache_ws.c
index a40bdbc1b..a8208d3a0 100644
--- a/bin/varnishd/cache/cache_ws.c
+++ b/bin/varnishd/cache/cache_ws.c
@@ -234,6 +234,7 @@ WS_ReserveAll(struct ws *ws)
 {
 	unsigned b;
 
+	WS_Assert(ws);
 	assert(ws->r == NULL);
 
 	ws->r = ws->e;