[master] e142af75d cache_backend: set the backend happy bitfield to all-one if no probe

[Nils Goroll]

commit e142af75decb675a554434a48e65e55bd0267f0c
Author: Nils Goroll <nils.goroll at uplex.de>
Date:   Mon Sep 30 18:46:31 2024 +0200

    cache_backend: set the backend happy bitfield to all-one if no probe
    
    Fixes #4201

diff --git a/bin/varnishd/cache/cache_backend.c b/bin/varnishd/cache/cache_backend.c
index 977933772..d3a98ac56 100644
--- a/bin/varnishd/cache/cache_backend.c
+++ b/bin/varnishd/cache/cache_backend.c
@@ -893,6 +893,7 @@ VRT_new_backend_clustered(VRT_CTX, struct vsmw_cluster *vc,
 		m = vbe_methods;
 	} else {
 		be->sick = 0;
+		be->vsc->happy = UINT64_MAX;
 		m = vbe_methods_noprobe;
 	}
 
diff --git a/bin/varnishtest/tests/v00003.vtc b/bin/varnishtest/tests/v00003.vtc
index 21fa9607e..b89680d74 100644
--- a/bin/varnishtest/tests/v00003.vtc
+++ b/bin/varnishtest/tests/v00003.vtc
@@ -17,10 +17,18 @@ varnish v1 -arg "-p vcl_cooldown=1" \
 		.port = "${s1_port}";
 		.probe = { .interval = 1s; }
 	}
+	backend noprobe {
+		.host = "${s1_addr}";
+		.port = "${s1_port}";
+	}
+	sub vcl_backend_fetch {
+		set bereq.backend = noprobe;
+	}
 } -start
 
 # We only have one vcl yet
 varnish v1 -expect VBE.vcl1.default.happy >= 0
+varnish v1 -expect VBE.vcl1.noprobe.happy > 9223372036854775808
 varnish v1 -expect !VBE.vcl2.default.happy
 varnish v1 -cliok "backend.list -p *.*"