* fix(injection): read WM_CLASS with xprop so xdotool stops dumping core
`xdotool getwindowclassname` hands an uninitialized XClassHint to XFree
when the window carries no WM_CLASS, so it aborts with SIGABRT
("free(): invalid size") and leaves a coredump behind. On KDE Plasma
Wayland that is the normal case, not an edge case: while a native
Wayland client holds focus, KWin points XWayland's _NET_ACTIVE_WINDOW at
a property-less window, and `xdotool getactivewindow` reports it happily.
Every paste-shortcut probe therefore killed a child process and filled
the journal with coredumps. Injection still worked, because the abort
only made the probe return an empty class, so the symptom was silent
except in `coredumpctl`.
read_wm_class() now reads the property with xprop, which handles a
missing WM_CLASS as an ordinary empty result, and falls back to xdotool
only when xprop is absent and the window looks like a real client (it has
a pid or a title). The debug window-info logging in text_injector.py goes
through the same helper.
Reproduced on Fedora 44, Plasma 6 Wayland, xdotool 3.20211022.1:
`xdotool getwindowclassname 0x200000` exits 134 on the window that
`_NET_ACTIVE_WINDOW` points at.
* fix(injection): keep xdotool classname for class-only X11 clients
When xprop is missing, always allow the xdotool classname fallback so a
real terminal that exposes WM_CLASS but no title or _NET_WM_PID still
classifies as a terminal (Ctrl+Shift+V). xprop remains the primary path,
so Plasma Wayland with xprop never calls getwindowclassname.
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Co-authored-by: Jatin K Malik <jatinkrmalik@gmail.com>
