Close VDPs for error conditions in cnt_transmit()

... and use the pedantic VDP to test that we do.

This should plug some less relevant memory leaks from VDPs which
allocate heap memory.

Note that we should not close VDPs for the happy path to allow
transports to keep them open until after cnt_transmit returns (e.g. in
vmod_pesi).

Calling VDP_Close() from cnt_transmit() avoids repetition for error
handling in transports.

bin/varnishd/cache/cache_req_fsm.c

@@ -496,6 +496,9 @@ cnt_transmit(struct worker *wrk, struct req *req)
 		req->doclose = SC_TX_ERROR;
 	}
 
+	if (req->doclose != SC_NULL)
+		req->acct.resp_bodybytes += VDP_Close(req->vdc);
+
 	if (boc != NULL)
 		HSH_DerefBoc(wrk, req->objcore);
 

bin/varnishtest/tests/r02618.vtc

@@ -6,11 +6,13 @@ server s1 {
 } -start
 
 varnish v1 -arg "-a ${tmpdir}/v1.sock" -vcl+backend {
+	import debug;
 	import vtc;
 	sub vcl_recv {
 		return (hash);
 	}
 	sub vcl_deliver {
+		set resp.filters += " debug.pedantic";
 		if (req.method == "GET") {
 			vtc.workspace_alloc(client, -1 * (req.xid - 1001));
 		} else if (req.method == "HEAD") {
@@ -28,18 +30,25 @@ varnish v1 -cliok "param.set vsl_mask -VCL_call,-VCL_return,-Hit"
 
 logexpect l1 -v v1 -g raw {
 	expect * *	VCL_Error	"Attempted negative WS allocation"
+	expect * *	Error		"Failure to push processors"
+	expect * *	VCL_Error	"Out of workspace for VDP_STATE_MAGIC"
+	expect * *	Error		"Failure to push processors"
 	expect * *	Error		"Failure to push v1d processor"
 	expect * *	VCL_Error	"Attempted negative WS allocation"
-	expect * *	Error		"workspace_client overflow"
+	expect * *	Error		"Failure to push processors"
+	expect * *	VCL_Error	"Out of workspace for VDP_STATE_MAGIC"
+	expect * *	Error		"Failure to push processors"
 } -start
 
 # some responses will fail (503), some won't. All we care
 # about here is the fact that we don't panic
 client c1 -connect "${tmpdir}/v1.sock" -repeat 100 {
+	non_fatal
 	txreq -url "/"
 	rxresp
 } -run
 client c1 -connect "${tmpdir}/v1.sock" -repeat 100 {
+	non_fatal
 	txreq -url "/" -method "HEAD"
 	rxresp
 } -run