From 2177de7b6e35499584731e6f4869903aa553022b Mon Sep 17 00:00:00 2001
From: Michal Privoznik <mprivozn@redhat.com>
Date: Wed, 8 Jun 2022 15:01:00 +0200
Subject: [PATCH] virsh: Check whether enough arguments was passed to
 iothreadset

Virsh has iothreadset command which allows setting various
attributes of IOThreads. However, when the command is called
without any arguments (besides domain and IOThread IDs), then
@params stays NULL and is passed to virDomainSetIOThreadParams()
which produces rather user unfriendly error message:

  error: params in virDomainSetIOThreadParams must not be NULL

Introduce a check and produce better error message.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Claudio Fontana <cfontana@suse.de>
---
 tools/virsh-domain.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/tools/virsh-domain.c b/tools/virsh-domain.c
index 5c4a7d7b8d..cfdaac1942 100644
--- a/tools/virsh-domain.c
+++ b/tools/virsh-domain.c
@@ -7853,6 +7853,11 @@ cmdIOThreadSet(vshControl *ctl, const vshCmd *cmd)
 
 #undef VSH_IOTHREAD_SET_UINT_PARAMS
 
+    if (nparams == 0) {
+        vshError(ctl, _("Not enough arguments passed, nothing to set"));
+        goto cleanup;
+    }
+
     if (virDomainSetIOThreadParams(dom, id, params, nparams, flags) < 0)
         goto cleanup;