in vmod destructors, tolerate failed object initializations

works around #2297

Conflicts:
	lib/libvmod_directors/fall_back.c
	lib/libvmod_directors/hash.c
	lib/libvmod_directors/random.c
	lib/libvmod_directors/round_robin.c

lib/libvmod_directors/fall_back.c

@@ -108,9 +108,11 @@ vmod_fallback__fini(struct vmod_directors_fallback **fbp)
 {
 	struct vmod_directors_fallback *fb;
 
-	fb = *fbp;
-	*fbp = NULL;
-	CHECK_OBJ_NOTNULL(fb, VMOD_DIRECTORS_FALLBACK_MAGIC);
+	// XXX 2297
+	if (*fbp == NULL)
+		return;
+
+	TAKE_OBJ_NOTNULL(fb, fbp, VMOD_DIRECTORS_FALLBACK_MAGIC);
 	vdir_delete(&fb->vd);
 	FREE_OBJ(fb);
 }

lib/libvmod_directors/hash.c

@@ -67,9 +67,11 @@ vmod_hash__fini(struct vmod_directors_hash **rrp)
 {
 	struct vmod_directors_hash *rr;
 
-	rr = *rrp;
-	*rrp = NULL;
-	CHECK_OBJ_NOTNULL(rr, VMOD_DIRECTORS_HASH_MAGIC);
+	// XXX 2297
+	if (*rrp == NULL)
+		return;
+
+	TAKE_OBJ_NOTNULL(rr, rrp, VMOD_DIRECTORS_HASH_MAGIC);
 	vdir_delete(&rr->vd);
 	FREE_OBJ(rr);
 }

lib/libvmod_directors/random.c

@@ -95,9 +95,11 @@ vmod_random__fini(struct vmod_directors_random **rrp)
 {
 	struct vmod_directors_random *rr;
 
-	rr = *rrp;
-	*rrp = NULL;
-	CHECK_OBJ_NOTNULL(rr, VMOD_DIRECTORS_RANDOM_MAGIC);
+	// XXX 2297
+	if (*rrp == NULL)
+		return;
+
+	TAKE_OBJ_NOTNULL(rr, rrp, VMOD_DIRECTORS_RANDOM_MAGIC);
 	vdir_delete(&rr->vd);
 	FREE_OBJ(rr);
 }

lib/libvmod_directors/round_robin.c

@@ -104,9 +104,11 @@ vmod_round_robin__fini(struct vmod_directors_round_robin **rrp)
 {
 	struct vmod_directors_round_robin *rr;
 
-	rr = *rrp;
-	*rrp = NULL;
-	CHECK_OBJ_NOTNULL(rr, VMOD_DIRECTORS_ROUND_ROBIN_MAGIC);
+	// XXX 2297
+	if (*rrp == NULL)
+		return;
+
+	TAKE_OBJ_NOTNULL(rr, rrp, VMOD_DIRECTORS_ROUND_ROBIN_MAGIC);
 	vdir_delete(&rr->vd);
 	FREE_OBJ(rr);
 }

lib/libvmod_directors/vmod_shard.c

@@ -265,6 +265,10 @@ vmod_shard__fini(struct vmod_directors_shard **vshardp)
 {
 	struct vmod_directors_shard *vshard;
 
+	// XXX 2297
+	if (*vshardp == NULL)
+		return;
+
 	TAKE_OBJ_NOTNULL(vshard, vshardp, VMOD_SHARD_SHARD_MAGIC);
 	sharddir_delete(&vshard->shardd);
 	free(vshard->dir->vcl_name);
@@ -795,8 +799,10 @@ vmod_shard_param__fini(struct vmod_directors_shard_param **pp)
 {
 	struct vmod_directors_shard_param *p;
 
+	// XXX 2297
 	if (*pp == NULL)
 		return;
+
 	TAKE_OBJ_NOTNULL(p, pp, VMOD_SHARD_SHARD_PARAM_MAGIC);
 	FREE_OBJ(p);
 }