Incompatible clipboard format between 32bit and 64bit cygwin

Thomas Wolff
Sun Sep 26 18:37:45 GMT 2021

Am 26.09.2021 um 11:50 schrieb Mark Geisert:
> Hi Takashi,
> Takashi Yano via Cygwin wrote:
>> I noticed that cygwin clipboard is not compatible
>> between 32bit and 64bit cygwin.
>> If I run 'echo AAAAAAAA > /dev/clipboard' in 32bit cygwin,
>> and run 'cat /dev/clipboard' in 64bit cygwin, this result in
>> cat: /dev/clipboard: Bad address
>> This is because the structure
>> typedef struct
>> {
>>    timestruc_t   timestamp;
>>    size_t    len;
>>    char      data[1];
>> } cygcb_t;
>> defined in has different size.
>> Is this the known issue?
> I doubt anybody has ever tried what you did. 
I have and it failed; I just didn't find it important enough to report 
it here... Thanks for the plan to fix it.

> I have been testing getclip and putclip between 32- and 64-bit 
> environments, but neglected to test Cygwin-internal clipboard format 
> that prepends cygcb_t to the user-supplied data.  So getclip and 
> putclip will need fixing as well.
> I will submit a Cygwin patch to fix /dev/clipboard usage and a similar 
> patch to cygutils for the utilities.
> I appreciate your help in uncovering and investigating bugs in 
> clipboard support.
> Thanks & Regards,
> ..mark

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