Resolve /dev/console to the active tty instead of just "tty0"

When resolving /dev/console one would often get "tty0" meaning the active VT.
Resolving to the actual tty (e.g. "tty1") will notably help on boot when
determining whether or not PID1 can output to the console.

1 files changed, 10 insertions, 0 deletions

diff --git a/src/shared/util.c b/src/shared/util.c
index 838885a464..b77d010d2d 100644
--- a/src/shared/util.c
+++ b/src/shared/util.c
@@ -3700,6 +3700,16 @@ char *resolve_dev_console(char **active) {
         else
                 tty = *active;
 
+        if (streq(tty, "tty0")) {
+                char *tmp;
+
+                /* Get the active VC (e.g. tty1) */
+                if (read_one_line_file("/sys/class/tty/tty0/active", &tmp) >= 0) {
+                        free(*active);
+                        tty = *active = tmp;
+                }
+        }
+
         return tty;
 }