[master] 0883512ed vmod_vtc: Add support for thread workspace operations on the backend side

[Nils Goroll]

commit 0883512edae29bf516e749f3ad5e68df25942fb4
Author: Nils Goroll <nils.goroll at uplex.de>
Date:   Mon Oct 28 10:09:49 2024 +0100

    vmod_vtc: Add support for thread workspace operations on the backend side
    
    This is probably useless at the moment because of how the vcl method code checks
    thread workspace allocations, but at least we avoid a panic at the wrong place.

diff --git a/vmod/vmod_vtc.c b/vmod/vmod_vtc.c
index 2d97b3543..191282b2b 100644
--- a/vmod/vmod_vtc.c
+++ b/vmod/vmod_vtc.c
@@ -142,8 +142,10 @@ vtc_ws_find(VRT_CTX, VCL_ENUM which)
 		return (ctx->bo->ws);
 	if (which == VENUM(session))
 		return (ctx->req->sp->ws);
-	if (which == VENUM(thread))
+	if (which == VENUM(thread) && ctx->req != NULL)
 		return (ctx->req->wrk->aws);
+	if (which == VENUM(thread) && ctx->bo != NULL)
+		return (ctx->bo->wrk->aws);
 	WRONG("vtc_ws_find Illegal enum");
 }