fix regression: ban-lurker skips objects

93d80501 made execution of
ban_lurker_test_ban() conditional on bd != b, which effectively caused
objects hanging off bans below request bans to not get tested against
relevant bans.

Because object bans (from the obans list) are being marked completed,
the objects which were skipped would also be missed to get evaluated
against the relevant bans at lookup time unless they were evaluated in
request context. So, in effect, we would simply miss to test bans.

Fixes #3007

Maybe related to #3006

bin/varnishd/cache/cache_ban_lurker.c

@@ -304,7 +304,7 @@ ban_lurker_test_ban(struct worker *wrk, struct vsl_log *vsl, struct ban *bt,
 			VSC_C_main->bans_lurker_obj_killed += lok;
 			VSC_C_main->bans_lurker_obj_killed_cutoff += lokc;
 			tested = tested_tests = lok = lokc = 0;
-			if (oc->ban == bt) {
+			if (oc->ban == bt && bt != bd) {
 				bt->refcount--;
 				VTAILQ_REMOVE(&bt->objcore, oc, ban_list);
 				oc->ban = bd;
@@ -356,7 +356,7 @@ ban_lurker_work(struct worker *wrk, struct vsl_log *vsl)
 	bd = NULL;
 	VTAILQ_INIT(&obans);
 	for (; b != NULL; b = VTAILQ_NEXT(b, list)) {
-		if (bd != NULL && bd != b)
+		if (bd != NULL)
 			ban_lurker_test_ban(wrk, vsl, b, &obans, bd,
 			    count > cutoff);
 		if (b->flags & BANS_FLAG_COMPLETED)

bin/varnishtest/tests/c00049.vtc

@@ -33,6 +33,15 @@ server s1 {
 	expect req.url == /4
 	txresp -hdr "Foo: bar4.1"
 
+	rxreq
+	expect req.url == /r1
+	txresp
+	rxreq
+	expect req.url == /r2
+	txresp
+	rxreq
+	expect req.url == /r3
+	txresp
 } -start
 
 varnish v1 -vcl+backend {} -start
@@ -132,8 +141,8 @@ varnish v1 -expect bans_deleted == 2
 varnish v1 -expect bans_tested == 0
 varnish v1 -expect bans_tests_tested == 0
 varnish v1 -expect bans_obj_killed == 0
-varnish v1 -expect bans_lurker_tested == 8
-varnish v1 -expect bans_lurker_tests_tested == 9
+varnish v1 -expect bans_lurker_tested == 10
+varnish v1 -expect bans_lurker_tests_tested == 11
 varnish v1 -expect bans_lurker_obj_killed == 4
 varnish v1 -expect bans_dups == 0
 
@@ -157,8 +166,8 @@ varnish v1 -expect bans_deleted == 2
 varnish v1 -expect bans_tested == 1
 varnish v1 -expect bans_tests_tested == 1
 varnish v1 -expect bans_obj_killed == 0
-varnish v1 -expect bans_lurker_tested == 8
-varnish v1 -expect bans_lurker_tests_tested == 9
+varnish v1 -expect bans_lurker_tested == 10
+varnish v1 -expect bans_lurker_tests_tested == 11
 varnish v1 -expect bans_lurker_obj_killed == 4
 varnish v1 -expect bans_dups == 0
 
@@ -182,8 +191,8 @@ varnish v1 -expect bans_deleted == 5
 varnish v1 -expect bans_tested == 2
 varnish v1 -expect bans_tests_tested == 2
 varnish v1 -expect bans_obj_killed == 1
-varnish v1 -expect bans_lurker_tested == 8
-varnish v1 -expect bans_lurker_tests_tested == 9
+varnish v1 -expect bans_lurker_tested == 10
+varnish v1 -expect bans_lurker_tests_tested == 11
 varnish v1 -expect bans_lurker_obj_killed == 4
 varnish v1 -expect bans_dups == 0
 
@@ -217,10 +226,41 @@ varnish v1 -expect bans_deleted == 10
 varnish v1 -expect bans_tested == 2
 varnish v1 -expect bans_tests_tested == 2
 varnish v1 -expect bans_obj_killed == 1
-varnish v1 -expect bans_lurker_tested == 8
-varnish v1 -expect bans_lurker_tests_tested == 9
+varnish v1 -expect bans_lurker_tested == 10
+varnish v1 -expect bans_lurker_tests_tested == 11
 varnish v1 -expect bans_lurker_obj_killed == 4
 varnish v1 -expect bans_lurker_obj_killed_cutoff == 3
 varnish v1 -expect bans_dups == 0
 
 varnish v1 -expect n_object == 0
+
+client c1 {
+	txreq -url /r1
+	rxresp
+} -run
+
+varnish v1 -cliok "ban req.http.nevermatch == 1"
+
+client c1 {
+	txreq -url /r2
+	rxresp
+} -run
+
+varnish v1 -cliok "ban req.http.nevermatch == 2"
+
+client c1 {
+	txreq -url /r3
+	rxresp
+} -run
+
+varnish v1 -cliok "ban req.http.nevermatch == 3"
+
+varnish v1 -cliok "ban.list"
+
+varnish v1 -cliok "ban obj.http.status != 0"
+
+delay 1
+
+varnish v1 -cliok "ban.list"
+
+varnish v1 -expect n_object == 0