Re: [libvirt] [PATCHv2 06/17] qemu: implement <model> subelement to <controller>

On 07/22/2015 03:54 PM, John Ferlan wrote:

>> + if (deviceName && >> + VIR_STRDUP(options->type, deviceName) < 0) >> + goto cleanup; >> + > As has been told to me before - virStrdup/VIR_STRDUP is "tolerant" of > deviceName == NULL returning 0 if it's NULL, so just: > > if (VIR_STRDUP(options->type, deviceName) < 0) > goto cleanup; > > is necessary But that would set options->type to NULL in the case that deviceName hadn't been set, and we don't want that. Consider for a moment that options->type had already been explicitly set to "pci-bridge". Since options->type != NULL, deviceName would remain NULL, we would get to the VIR_STRDUP() and unconditionally set options->type to NULL, losing the value that we actually wanted (and leaking it to boot). Hmm. I guess my logic *is* a bit backwards though :-) Instead I should say "if (!options->type && VIR_STRDUP(blah)...)"