Re: [PATCH] ui/clipboard: avoid crash upon request when clipboard peer is not initialized

[Fiona Ebner <f.ebner@proxmox.com>]

Am 14.01.24 um 14:51 schrieb Marc-André Lureau:
>>
>> diff --git a/ui/clipboard.c b/ui/clipboard.c
>> index 3d14bffaf8..c13b54d2e9 100644
>> --- a/ui/clipboard.c
>> +++ b/ui/clipboard.c
>> @@ -129,7 +129,8 @@ void qemu_clipboard_request(QemuClipboardInfo *info,
>>      if (info->types[type].data ||
>>          info->types[type].requested ||
>>          !info->types[type].available ||
>> -        !info->owner)
>> +        !info->owner ||
>> +        !info->owner->request)
>>          return;
> 
> While that fixes the crash, I think we should handle the situation
> earlier. A clipboard peer shouldn't be allowed to hold the clipboard
> if it doesn't have the data available or a "request" callback set.
> 

Where should initialization of the cbpeer happen so that we are
guaranteed to do it also for clients that do not set the
VNC_FEATURE_CLIPBOARD_EXT feature? Can the vnc_clipboard_request
function be re-used for clients without that feature or will it be
necessary to add some kind of "dummy" request callback for those clients?

> Iow, we should have an assert(info->owner->request != NULL) here instead.
>
Your choice of course, but it would be a crash again should the issue
ever re-appear. Would error message (so the issue gets noticed) + return
be an option too?

Best Regards,
Fiona