[PATCH] Cygwin: Make native clipboard layout same for 32- and 64-bit

[Mark Geisert]

Hi all,

Corinna Vinschen wrote:
> On Oct 11 08:11, Ken Brown wrote:
>> On 10/11/2021 2:13 AM, Mark Geisert wrote:
>>> It's just that after submitting the patch I realized that, if we really
>>> are going to support both Cygwin archs (x86_64 and i686), there is still
>>> the issue of different cygcb_t layouts between Cygwin versions being
>>> ignored.
>>>
>>> Specifically, the fhandler_clipboard::fstat routine can't tell which
>>> Cygwin environment has set the clipboard contents.  My original patch
>>> takes care of 32-bit and 64-bit, providing both are running Cygwin >=
>>> 3.3.0 (presumably).  What if it was a different version (pre 3.3.0) that
>>> set the contents?
>>
>> I wonder if this is worth the trouble.  Right now we have a problem in which
>> data written to /dev/clipboard in one arch can't be read in the other arch.
>> The fix will appear in Cygwin 3.3.0.  Do we really have to try to make the
>> fix apply retroactively in case the user updates one arch but not the other?
> 
> Just to close this up prior to the 3.3.0 release...
> 
> Given we never actually strived for 32<->64 bit interoperability, it's
> hard to argue why this should be different for the clipboard stuff.
> 
> Running 32 and 64 bit Cygwin versions in parallel doesn't actually make
> much sense for most people anyway, unless they explicitely develop for
> 32 and 64 bit systems under Cygwin.  From a productivity point of view
> there's no good reason to run more than one arch.
> 
> So I agree with Ken here.  It's probably not worth the trouble.

Sorry, I've been sidetracked for a bit.  I can agree with Ken too.  The only 
circumstance I could think of where multiple internal format support might be 
useful (to non-developers) was some user hanging on to an older Cygwin because it 
was needed to support something else (s/w or h/w) old and non-upgradeable. 
Doesn't seem very likely at this point.

I'll try to get the v2 patch out over this weekend.  Same end-result for same 
environments as the v1 patch, but incorporating all the comments I received.

To that end, does Jon's suggestion of /usr/include/sys/cygwin.h seem like the best 
location to define struct cygcb_t for use by both Cygwin and cygutils package?
Thanks much,

..mark