[master] d6e5852e5 Support calling debug.return_strands() from vcl_init {}

[Nils Goroll]

commit d6e5852e50513976af11a5c90dee0daec65eabb5
Author: Nils Goroll <nils.goroll at uplex.de>
Date:   Thu Aug 1 12:17:11 2024 +0200

    Support calling debug.return_strands() from vcl_init {}

diff --git a/vmod/vmod_debug.c b/vmod/vmod_debug.c
index e2e42ee51..026ca0dd5 100644
--- a/vmod/vmod_debug.c
+++ b/vmod/vmod_debug.c
@@ -977,7 +977,10 @@ xyzzy_return_strands(VRT_CTX, VCL_STRANDS strand)
 {
 
 	CHECK_OBJ_NOTNULL(ctx, VRT_CTX_MAGIC);
-	VSLbs(ctx->vsl, SLT_Debug, strand);
+	if (ctx->vsl)
+		VSLbs(ctx->vsl, SLT_Debug, strand);
+	else
+		VSLs(SLT_Debug, NO_VXID, strand);
 	return (strand);
 }