qemu: handle -1 for pid in qemuDomainGetMachineName

We call qemuDomainGetMachineName on domain start. On first
start (after daemon start) pid is 0 and virSystemdGetMachineNameByPID
don't get called. But after domain shutting down pid became -1 so
on next start virSystemdGetMachineNameByPID is called and returned an error.
Error is ignored so it is not critical. But at least on my system
(systemd-219 with extra patches) systemd-machined is crashed on
this request.

This behaviour is triggered by eaf2c9f89.

Reviewed-by: Daniel P. Berrange <berrange@redhat.com>

diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index cbee151f5d3d21cf26678a64a99ccbac494cd46e..b98ffffae21c70c8f7c2a5910b0dbd9a9b03b456 100644 (file)
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -9781,7 +9781,7 @@ qemuDomainGetMachineName(virDomainObjPtr vm)
     virQEMUDriverPtr driver = priv->driver;
     char *ret = NULL;
 
-    if (vm->pid) {
+    if (vm->pid > 0) {
         ret = virSystemdGetMachineNameByPID(vm->pid);
         if (!ret)
             virResetLastError();