Use WS_Copy() for task-scoped .arg() rather than strdup().

src/vdfp_pipe.c

@@ -672,11 +672,8 @@ task_free(void *p)
 	struct task_cfg *task;
 
 	CAST_OBJ_NOTNULL(task, p, PIPE_TASK_MAGIC);
-	if (task->argv != NULL) {
-		for (int i = 1; task->argv[i] != NULL; i++)
-			free(task->argv[i]);
+	if (task->argv != NULL)
 		free(task->argv);
-	}
 }
 
 VCL_VOID
@@ -720,8 +717,8 @@ vmod_vdp_arg(VRT_CTX, struct VPFX(pipe_vdp) *obj, VCL_STRING arg)
 	AN(priv);
 	if (priv->priv == NULL) {
 		if ((priv->priv = WS_Alloc(ctx->ws, sizeof(*task))) == NULL) {
-			VDPFAIL(ctx, "%s.arg(): cannot allocate task config",
-				obj->name);
+			VDPFAIL(ctx, "%s.arg(): insufficient workspace for "
+				"task config", obj->name);
 			return;
 		}
 		task = (struct task_cfg *)priv->priv;
@@ -732,8 +729,12 @@ vmod_vdp_arg(VRT_CTX, struct VPFX(pipe_vdp) *obj, VCL_STRING arg)
 				obj->name, vstrerror(errno));
 			return;
 		}
+		if ((task->argv[1] = WS_Copy(ctx->ws, arg, -1)) == NULL) {
+			VDPFAIL(ctx, "%s.arg(): insufficient workspace for %s",
+				obj->name, arg);
+			return;
+		}
 		task->argv[0] = obj->path;
-		task->argv[1] = strdup(arg);
 		task->argv[2] = NULL;
 		task->argc = 2;
 		task->magic = PIPE_TASK_MAGIC;
@@ -754,7 +755,11 @@ vmod_vdp_arg(VRT_CTX, struct VPFX(pipe_vdp) *obj, VCL_STRING arg)
 			vstrerror(errno));
 		return;
 	}
-	task->argv[task->argc] = strdup(arg);
+	if ((task->argv[task->argc] = WS_Copy(ctx->ws, arg, -1)) == NULL) {
+		VDPFAIL(ctx, "%s.arg(): insufficient workspace for %s",
+			obj->name, arg);
+		return;
+	}
 	task->argv[task->argc + 1] = NULL;
 	task->argc++;