Also zap keep when purging.

Fixes #1139

bin/varnishd/cache/cache_hash.c

@@ -555,7 +555,8 @@ hsh_rush(struct dstat *ds, struct objhead *oh)
  */
 
 void
-HSH_Purge(struct worker *wrk, struct objhead *oh, double ttl, double grace)
+HSH_Purge(struct worker *wrk, struct objhead *oh, double ttl, double grace,
+double keep)
 {
 	struct objcore *oc, **ocp;
 	unsigned spc, nobj, n;
@@ -598,7 +599,7 @@ HSH_Purge(struct worker *wrk, struct objhead *oh, double ttl, double grace)
 		if (o == NULL)
 			continue;
 		CHECK_OBJ_NOTNULL(o, OBJECT_MAGIC);
-		EXP_Rearm(o, now, ttl, grace, NAN);	// XXX: Keep ?
+		EXP_Rearm(o, now, ttl, grace, keep);
 		(void)HSH_DerefObj(&wrk->stats, &o);
 	}
 	WS_Release(wrk->aws, 0);

bin/varnishd/cache/cache_req_fsm.c

@@ -825,7 +825,7 @@ cnt_purge(struct worker *wrk, struct req *req)
 	CHECK_OBJ_NOTNULL(boc, OBJCORE_MAGIC);
 	VRY_Finish(req, DISCARD);
 
-	HSH_Purge(wrk, boc->objhead, 0, 0);
+	HSH_Purge(wrk, boc->objhead, 0, 0, 0);
 
 	AZ(HSH_DerefObjCore(&wrk->stats, &boc));
 

bin/varnishd/cache/cache_vrt.c

@@ -492,10 +492,10 @@ VRT_purge(const struct vrt_ctx *ctx, double ttl, double grace)
 	CHECK_OBJ_NOTNULL(ctx->req->wrk, WORKER_MAGIC);
 	if (ctx->method == VCL_MET_HIT)
 		HSH_Purge(ctx->req->wrk, ctx->req->obj->objcore->objhead,
-		    ttl, grace);
+		    ttl, grace, NAN);
 	else if (ctx->method == VCL_MET_MISS)
 		HSH_Purge(ctx->req->wrk, ctx->req->objcore->objhead,
-		    ttl, grace);
+		    ttl, grace, NAN);
 }
 
 /*--------------------------------------------------------------------

bin/varnishd/hash/hash_slinger.h

@@ -70,7 +70,8 @@ void HSH_Drop(struct worker *, struct object **);
 void HSH_Init(const struct hash_slinger *slinger);
 void HSH_AddString(const struct req *, const char *str);
 void HSH_Insert(struct worker *, const void *hash, struct objcore *);
-void HSH_Purge(struct worker *, struct objhead *, double ttl, double grace);
+void HSH_Purge(struct worker *, struct objhead *, double ttl, double grace,
+    double keep);
 void HSH_config(const char *h_arg);
 struct busyobj *HSH_RefBusy(const struct objcore *oc);
 struct objcore *HSH_Private(struct worker *wrk);