fix: use wl-copy for clipboard writes on native Wayland sessions

[jb0421]

Summary

Fixes #12534

On native Wayland sessions, QApplication::clipboard()->setText() is silently
dropped by the compositor when the ownCloud daemon has no focused surface — which
is always the case when the command arrives via the socket from a file manager
shell integration.

This change detects a native Wayland session via WAYLAND_DISPLAY and delegates
the clipboard write to wl-copy(1), which uses the Wayland primary selection
protocol and does not require a compositor surface.

Changes

• copyUrlToClipboard(): fall back to wl-copy when WAYLAND_DISPLAY is set
• Add #include <QProcess>
• Add changelog entry for COPY_PRIVATE_LINK and COPY_PUBLIC_LINK silently fail on native Wayland sessions #12534

Testing

Tested manually on Ubuntu 24.04 LTS (GNOME Wayland, Nautilus 46.4) with a locally
built client:

• Before: right-click → "Copy private link" → clipboard empty
• After: right-click → "Copy private link" → URL correctly pasted

Notes

wl-copy is provided by the wl-clipboard package, which is available on all
major Linux distributions and is a common dependency for Wayland clipboard tools.
If wl-copy is not installed, QProcess::startDetached silently fails and the
clipboard write is lost — same behaviour as before this fix.

See also: owncloud/client-desktop-shell-integration-nautilus#11 (comment)

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[DeepDiver1975]

Interesting approach indeed ..... requires wl-copy to be installed .... also needs to be ltested with the appimage - I guess we would need wl-copy to be packaged into the app image ...

[jb0421]

@DeepDiver1975 Should I create a new PR with wl-clipboard packaged into the AppImage, or do you as a Maintainer want to take over from here?

[DeepDiver1975]

Should I create a new PR with wl-clipboard packaged into the AppImage

feel free to give it a shot - thank you

[jb0421]

@DeepDiver1975 Now it bundles wl-copy within the AppImage.

[dj4oC]

Adds a Wayland-specific clipboard write path (spawns wl-copy) for "Copy private link to clipboard" instead of always using QApplication::clipboard().

Findings

Security: Medium — falls back to a bare "wl-copy" resolved via $PATH when no bundled binary is found next to the app; a writable-earlier-in-PATH binary could be planted and executed with the private-link URL as an argument. Prefer a fixed system path (e.g. /usr/bin/wl-copy) or an explicit allow-list instead of trusting ambient PATH. Argument injection via URLs starting with - is a low-severity edge case (a -- separator would be cheap defense-in-depth). QProcess::startDetached is called with an argv list (not a shell string), which correctly avoids shell/command injection.

Stability: Concern — the branch triggers on any non-empty WAYLAND_DISPLAY, including XWayland-forced sessions (QT_QPA_PLATFORM=xcb) where the old QApplication::clipboard() path already worked; those users lose a previously-working path with no fallback. wl-copy also requires the wlr-data-control-unstable-v1 protocol, which GNOME/Mutter does not implement — on GNOME Wayland this silently no-ops, with no error surfaced to the user. Recommend falling back to QApplication::clipboard() when wl-copy isn't found or fails, rather than silently dropping the copy.

Performance: Clean — one stat() + a detached, non-blocking process spawn per user click; no UI-thread blocking, no hot loop.

Coverage: Minor gap — the binary-resolution logic is pure/testable but inlined in copyUrlToClipboard; no test added. Not blocking given this is UI/clipboard glue rather than sync logic.

Cross-platform check

Clean — change is scoped behind qgetenv("WAYLAND_DISPLAY") and if(UNIX AND NOT APPLE) in CMake; Windows/macOS unaffected.

Verdict

Changes requested

🤖 Automated review by Claude Code (security · stability · performance · coverage)

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