Andrew Hamilton
08202dc6c3
GDK_BACKEND/QT_QPA_PLATFORM forced to wayland stripped toolkits' fallback,
killing X11-only builds like emacs-gtk ('cannot open display' against a
healthy Xwayland). Children now self-select from WAYLAND_DISPLAY/DISPLAY,
and XAUTHORITY is cleared.
Separately, X11 membership decisions moved from window-creation time to
first map: GTK leader windows never map, yet claimed the tab slot at
creation, leaving a permanent black tab while the real frame was demoted
to a stacked member -- and Alt-cycling onto that phantom main member
crashed on wlr_seat_keyboard_notify_enter(NULL). Never-mapped windows now
free silently; keyboard-entry paths guard on live surfaces. New
tests/xleader.c probe (unmapped leader + mapped frame) locks the behaviour
in.
85 lines
2.9 KiB
C
85 lines
2.9 KiB
C
/* xleader: an X11 twin-window probe that mimics how GTK apps appear on
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* X11 -- an invisible "leader" window is created first and never mapped,
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* then the real frame maps. A compositor that claims windows at map time
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* (instead of creation time) gives this program exactly one tab; one that
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* claims at creation time steals the tab slot for the leader, which then
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* renders as a permanent black tab while the real frame gets demoted to a
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* tab-group member.
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*
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* Both windows carry _NET_WM_PID so process-group matching can claim them.
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* The frame fills itself with a solid colour so pixel checks can tell it
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* apart from an unrendered tab.
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*
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* Build: cc xleader.c -o xleader -lX11 $(pkg-config --cflags xcb xcb-icccm)
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*/
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#include <X11/Xlib.h>
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#include <X11/Xatom.h>
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#include <X11/Xutil.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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static void set_pid(Display *d, Window w) {
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pid_t pid = getpid();
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Atom net_pid = XInternAtom(d, "_NET_WM_PID", False);
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XChangeProperty(d, w, net_pid, XA_CARDINAL, 32, PropModeReplace,
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(unsigned char *)&pid, 1);
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}
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static void fill_frame(Display *d, Window w, int wpx, int hpx)
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{
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XWMHints hints;
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memset(&hints, 0, sizeof(hints));
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hints.flags = InputHint | StateHint;
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hints.input = True;
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hints.initial_state = NormalState;
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XSetWMHints(d, w, &hints);
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XGCValues gcv;
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GC gc = XCreateGC(d, w, 0, &gcv);
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XSetForeground(d, gc, 0x306090UL); /* muted blue: visible, not black */
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XFillRectangle(d, w, gc, 0, 0, wpx, hpx);
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XFreeGC(d, gc);
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XFlush(d);
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}
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int main(int argc, char **argv)
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{
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int wpx = argc > 1 ? atoi(argv[1]) : 640;
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int hpx = argc > 2 ? atoi(argv[2]) : 480;
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Display *d = XOpenDisplay(NULL);
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if (!d) {
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fprintf(stderr, "xleader: cannot open display\n");
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return 1;
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}
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int scr = DefaultScreen(d);
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Window root = RootWindow(d, scr);
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/* The leader: created, given WM_CLASS + pid, never mapped. */
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Window leader = XCreateSimpleWindow(d, root, 0, 0, 8, 8, 0, 0, 0);
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XStoreName(d, leader, "xleader-leader");
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set_pid(d, leader);
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/* The real frame: created and mapped. The background pixel is the
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probe colour so the window stays "filled" even right after a resize
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clears its backing pixmap (before any Expose-driven repaint lands). */
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Window frame = XCreateSimpleWindow(d, root, 0, 0, wpx, hpx, 0,
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BlackPixel(d, scr),
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0x306090UL);
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XStoreName(d, frame, "xleader-frame");
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set_pid(d, frame);
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XSelectInput(d, frame, ExposureMask | StructureNotifyMask);
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XMapWindow(d, frame);
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fill_frame(d, frame, wpx, hpx);
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XFlush(d);
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for (;;) {
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XEvent ev;
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XNextEvent(d, &ev); /* blocks: keeps the client alive */
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if (ev.type == Expose && ev.xexpose.window == frame)
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fill_frame(d, frame, wpx, hpx); /* stay painted after resizes */
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}
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return 0;
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}
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