[Wayland] Failed to send all clipoard data to XWayland window

[ToxicMushroom]

Describe the bug
When trying to paste large images, copyq shows a warning after pasting the first 65536 (2^16) bytes

To Reproduce
Steps to reproduce the behavior:

1. Copy an image larger than +- 66KB
2. Double click the copyq entry to select the entry for pasting
3. Try to paste the image in a program that runs via XWayland (e.g. gimp)

Expected behavior
The full image is pasted like when copying straigh from source to the XWayland program.

Screenshots
Demonstration.
https://user-images.githubusercontent.com/32853531/212791020-7f8a2788-5937-4cab-98f2-9748a086e9fe.mp4

copyq log

merlijn@arch ~ % copyq
Warning: [qt.qpa.wayland] QtWarning: Wayland does not support QWindow::requestActivate()
Warning: [default] QtWarning: Failed to send all clipobard data; sent 65536 bytes out of 1686475
Warning: [qt.qpa.wayland] QtWarning: Wayland does not support QWindow::requestActivate()
Warning: [default] QtWarning: Failed to send all clipobard data; sent 65536 bytes out of 1686475

env

LOGNAME=merlijn
MAIL=/var/spool/mail/merlijn
MOTD_SHOWN=pam
MOZ_ENABLE_WAYLAND=1
OLDPWD=/home/merlijn/example
PAGER=less
PATH=/usr/local/sbin:/usr/local/bin:/usr/bin:/opt/android-sdk/platform-tools:/home/merlijn/.dotnet/tools:/usr/lib/jvm/default/bin:/usr/bin/site_perl:/usr/bin/vendor_perl:/usr/bin/core_perl
PWD=/home/merlijn
QT_QPA_PLATFORM=wayland
SDL_VIDEODRIVER=wayland
SHELL=/bin/zsh
SHLVL=2
SWAYSOCK=/run/user/1000/sway-ipc.1000.586.sock
SYSTEMD_EXEC_PID=543
TERM=alacritty
USER=merlijn
WAYLAND_DISPLAY=wayland-1
WINDOWID=94412397509648
XCURSOR_SIZE=24
XDG_ACTIVATION_TOKEN=f57c22d4e2e4084ce93c3a7d5e0a162a
XDG_CURRENT_DESKTOP=sway
XDG_RUNTIME_DIR=/run/user/1000
XDG_SEAT=seat0
XDG_SESSION_CLASS=user
XDG_SESSION_DESKTOP=sway
XDG_SESSION_ID=1
XDG_SESSION_TYPE=wayland
XDG_VTNR=1
_=/usr/bin/env
_JAVA_AWT_WM_NONREPARENTING=1
LC_MESSAGES=

Version, OS and Environment

• CopyQ Clipboard Manager 6.3.2
• Qt: 5.15.6
• KNotifications: 5.98.0
• Compiler: GCC
• Arch: x86_64-little_endian-lp64
• OS: Arch Linux
• OS [e.g. Windows]
• DE: sway version 1.8

Additional context
This issue does not occur when using QT_QPA_PLATFORM=xbc or when pasting into wayland native programs.
I tried an online image editor on ungoogled-chromium under XWayland and native to deduce the above.
However due to #2224 using this workaround under wayland is undesirable.

[hluk]

Similar problem with Krita. Seem that it could be a problem with XWayland integration. Not sure if I can fix that in CopyQ.

[hluk]

All works if I pass the image data to wl-copy instead:

copyq clipboard image/png | wl-copy --type image/png

There is some problem passing the data via pipe (it gets interrupted after 64k is written - buffer size?):

CopyQ/src/platform/x11/systemclipboard/waylandclipboard.cpp

Line 86 in d6c4582

const qint64 written = c.write(m_data);

[hluk]

I checked the how wl-copy implements sending the data and it seems CopyQ is missing fcntl(fd, F_SETFL, 0) for the pipe.

[hluk]

Thanks for the detailed report. I will release the fix in the next version.