Merged changes from hunter. Attempt to fix cthulhu announcing modifiers when suspended for xterm.

tests/xorg_suspension_probe.c

@@ -2,15 +2,33 @@
 // but remains in Xlib's queue when the Go owner gives the keyboard back.
 #include "commands_native.h"
 #include <X11/keysym.h>
+#include <X11/XKBlib.h>
 #include <X11/extensions/XTest.h>
 #include <stdio.h>
 #include <string.h>
 
 int main(int argc, char **argv) {
     int error = 0, failed = 0;
-    CommandDevice *device = open_commands(1, 0, 0, &error);
+    int capsHandoff = argc == 2 && strcmp(argv[1], "caps-handoff") == 0;
+    CommandDevice *device = open_commands(1, 0, capsHandoff, &error);
     if (!device) { fprintf(stderr, "open: %d\n", error); return 1; }
-    if (argc == 2 && strcmp(argv[1], "queued") == 0) {
+    if (capsHandoff) {
+        set_command_keys(device, 0);
+        // A terminal reader changes the real lock while Cthulhu is suspended.
+        XkbLockModifiers(device->display, XkbUseCoreKbd, LockMask, LockMask);
+        XSync(device->display, False);
+        if (!(command_lock_state(device) & 1)) {
+            fprintf(stderr, "suspended lock read used stale reader state\n");
+            failed = 1;
+        }
+        set_command_keys(device, 1);
+        if (!device->capsLocked) {
+            fprintf(stderr, "resumed reader did not adopt external Caps Lock state\n");
+            failed = 1;
+        }
+        XkbLockModifiers(device->display, XkbUseCoreKbd, LockMask, 0);
+        XSync(device->display, False);
+    } else if (argc == 2 && strcmp(argv[1], "queued") == 0) {
         if (XGrabKeyboard(device->display, device->root, False,
                           GrabModeAsync, GrabModeAsync, CurrentTime) != GrabSuccess) return 1;
         device->active = 1;