Merge pull request #12378 from rbalint/vt-kbd-reset-check

VT kbd reset check

src/basic/terminal-util.c

@@ -1249,12 +1249,36 @@ int vt_default_utf8(void) {
         return parse_boolean(b);
 }
 
+int vt_verify_kbmode(int fd) {
+        int curr_mode;
+
+        /*
+         * Make sure we only adjust consoles in K_XLATE or K_UNICODE mode.
+         * Otherwise we would (likely) interfere with X11's processing of the
+         * key events.
+         *
+         * http://lists.freedesktop.org/archives/systemd-devel/2013-February/008573.html
+         */
+
+        if (ioctl(fd, KDGKBMODE, &curr_mode) < 0)
+                return -errno;
+
+        return IN_SET(curr_mode, K_XLATE, K_UNICODE) ? 0 : -EBUSY;
+}
+
 int vt_reset_keyboard(int fd) {
-        int kb;
+        int kb, r;
 
         /* If we can't read the default, then default to unicode. It's 2017 after all. */
         kb = vt_default_utf8() != 0 ? K_UNICODE : K_XLATE;
 
+        r = vt_verify_kbmode(fd);
+        if (r == -EBUSY) {
+                log_debug_errno(r, "Keyboard is not in XLATE or UNICODE mode, not resetting: %m");
+                return 0;
+        } else if (r < 0)
+                return r;
+
         if (ioctl(fd, KDSKBMODE, kb) < 0)
                 return -errno;
 

src/basic/terminal-util.h

@@ -156,6 +156,7 @@ int openpt_in_namespace(pid_t pid, int flags);
 int open_terminal_in_namespace(pid_t pid, const char *name, int mode);
 
 int vt_default_utf8(void);
+int vt_verify_kbmode(int fd);
 int vt_reset_keyboard(int fd);
 int vt_restore(int fd);
 int vt_release(int fd, bool restore_vt);