Re: [libvirt] [PATCH] conf: avoid libvirt crash with empty address guestfwd channel

The 'def->target.addr' hasn't been initialized in virDomainChrDefNew() and its value is always '0xffffffff', in addition, the following test scenario hasn't also include 'port' element in channel XML block, so the branch 'if (addrStr == NULL)' is hit in virDomainChrDefParseTargetXML(), the programming jumps to 'error' label to release relevant resources, and the statement 'if (VIR_ALLOC(def->target.addr) < 0)' hasn't been executed then the virDomainChrDefFree() will free 'def->target.addr'(0xffffffff) via VIR_FREE(), which results in libvirt crash, to use valgrind can also find a 'Invalid free() / delete / delete[]' error. This patch just adjusts codes order to initialize 'def->target.addr' firstly. With this patch, libvirt hasn't crash and can get a expected error message " XML error: guestfwd channel does not define a target address".