Add a 'blind' mode to do_bootloader, use it in notifications test

This makes it just keep hitting left until the boot menu shows up
(rather like a human would), instead of trying to see the boot menu
before pressing a key.

It seems like the notifications test on aarch64 often fails because
we somehow don't match the boot menu even though it shows up for
5 seconds. I don't understand why not, but this should hopefully
work around it, let's see.

Signed-off-by: Adam Williamson <awilliam@redhat.com>

lib/utils.pm

@@ -396,6 +396,7 @@ sub do_bootloader {
         timeout => 30,
         uefi => get_var("UEFI"),
         ofw => get_var("OFW"),
+        blind => 0,
         @_
     );
     my $relnum = get_release_number;
@@ -403,9 +404,17 @@ sub do_bootloader {
     # sure we actually did a UEFI boot
     my $boottag = "bootloader_bios";
     $boottag = "bootloader_uefi" if ($args{uefi});
-    assert_screen $boottag, $args{timeout};
+    if ($args{blind}) {
+        # press left, which should harmlessly interrupt the countdown,
+        # till we match on the screen
+        send_key_until_needlematch($boottag, 'left', $args{timeout}, 1);
+    }
+    else {
+        assert_screen $boottag, $args{timeout};
+    }
     if ($args{mutex}) {
         # cancel countdown
+        # repeated if we're in blind mode, but should be harmless
         send_key "left";
         mutex_lock $args{mutex};
         mutex_unlock $args{mutex};

tests/desktop_notifications.pm

@@ -26,10 +26,10 @@ sub _handle_bootloader {
     # boot with '3' to get to a console. factored out of run() as
     # it's repeated on the update flow
     if (get_var("BOOTFROM")) {
-        do_bootloader(postinstall => 1, params => '3');
+        do_bootloader(postinstall => 1, params => '3', blind => 1);
     }
     else {
-        do_bootloader(postinstall => 0, params => '3');
+        do_bootloader(postinstall => 0, params => '3', blind => 1);
     }
 }