[libvirt] Memory leak due to virCopyError()

[Stefan Berger]

If someone has the time ... I am seeing a memory leak in this code path. 
The leak seems to be triggerable by shutting down a VM:

==4717== 40 bytes in 1 blocks are definitely lost in loss record 547 of 
1,014
==4717==    at 0x4A05E46: malloc (vg_replace_malloc.c:195)
==4717==    by 0x38EC27FC01: strdup (strdup.c:43)
==4717==    by 0x4EA55E0: virCopyError (virterror.c:255)
==4717==    by 0x4EA58B1: virCopyLastError (virterror.c:356)
==4717==    by 0x4CB4B6: qemuMonitorIO (qemu_monitor.c:646)
==4717==    by 0x4E80C7F: virEventPollDispatchHandles (event_poll.c:490)
==4717==    by 0x4E8150B: virEventPollRunOnce (event_poll.c:637)
==4717==    by 0x4E7F5B7: virEventRunDefaultImpl (event.c:247)
==4717==    by 0x4FA4F50: virNetServerRun (virnetserver.c:713)
==4717==    by 0x4221AF: main (libvirtd.c:1133)

My guess is the leak is related to the initialization of the error 
structure as for example here:

int
virConnCopyLastError(virConnectPtr conn, virErrorPtr to)
{
     /* We can't guarantee caller has initialized it to zero */
     memset(to, 0, sizeof(*to));

     if (conn == NULL)
         return -1;
     virMutexLock(&conn->lock);
     if (conn->err.code == VIR_ERR_OK)
         virResetError(to);
     else


After memset'ting 'to' to all zeros, the call to virResetError() seems 
pointless... Such memsets are also in other places potentially 
overwriting previously allocated pointers...

    Stefan