From: Brian Inglis <Brian.Inglis@SystematicSw.ab.ca>
To: cygwin@cygwin.com
Subject: Re: Incompatible clipboard format between 32bit and 64bit cygwin
Date: Tue, 28 Sep 2021 00:46:15 -0600 [thread overview]
Message-ID: <82c34eff-3913-785c-7e77-aadc9d257d60@SystematicSw.ab.ca> (raw)
In-Reply-To: <20210928151936.2e644c2ebc717dc367e63003@nifty.ne.jp>
On 2021-09-28 00:19, Takashi Yano via Cygwin wrote:
> On Mon, 27 Sep 2021 23:22:30 -0600
> Brian Inglis wrote:
>> On 2021-09-27 22:49, Mark Geisert wrote:
>>> Hi Thomas,
>>>
>>> Thomas Wolff wrote:
>>>>
>>>> Am 26.09.2021 um 20:37 schrieb Thomas Wolff:
>>>>>
>>>>> 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 fhandler_clipboard.cc 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.
>>>> As we're at it, what's the purpose of a cygwin-internal clipboard
>>>> format at all?
>>>> Copy/paste between 32bit/64bit mintty works; mintty uses Windows
>>>> CF_UNICODETEXT clipboard format.
>>>
>>> The cygwin-internal clipboard format records a timestamp and content
>>> length when Cygwin (or putclip) updates the clipboard contents. This
>>> allows 'stat' and fstat() to show something sensible for
>>> /dev/clipboard. The latter feature went into Cygwin 1.7.13.
>>>
>>> Other than that, not much difference to CF_UNICODETEXT ;-).
>>
>> Would it perhaps make sense to include struct stat with appropriate
>> entries rather than a couple of adhoc members unrelated to much else?
>
> struct stat also has different size between 32 and 64 bit environment,
> therefore, it does not resolve the issue.
I didn't think any of those types varied by architecture, given the same
underlying file systems are supported, except the trailing long
st_spare4[2]; if it does, your proposal is better.
> I imagine using structure such as
> typedef struct
> {
> struct {
> int64_t tv_sec;
> int64_t tv_nsec;
> } timestamp;
> int64_t len;
> char data[1];
> } cygcb_t;
> rather than
> typedef struct
> {
> struct timespec timestamp;
> size_t len;
> char data[1];
> } cygcb_t;
--
Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada
This email may be disturbing to some readers as it contains
too much technical detail. Reader discretion is advised.
[Data in binary units and prefixes, physical quantities in SI.]
next prev parent reply other threads:[~2021-09-28 6:46 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-26 1:33 Takashi Yano
2021-09-26 9:50 ` Mark Geisert
2021-09-26 18:37 ` Thomas Wolff
2021-09-26 18:41 ` Thomas Wolff
2021-09-26 19:09 ` Lee
2021-09-26 20:46 ` Brian Inglis
2021-09-28 4:49 ` Mark Geisert
2021-09-28 5:22 ` Brian Inglis
2021-09-28 6:19 ` Takashi Yano
2021-09-28 6:46 ` Brian Inglis [this message]
2021-09-28 8:13 ` Takashi Yano
2021-09-28 17:11 ` Mark Geisert
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