GRUB_HIDDEN_TIMEOUT is badly documented

[Chris Bainbridge]

$ info -f grub -n 'Simple configuration'

`GRUB_HIDDEN_TIMEOUT'
     Wait this many seconds for a key to be pressed before displaying
     the menu. If no key is pressed during that time, boot
     immediately. Unset by default.

The documentation above does not state what the default actually is. I read it as implied that when GRUB_HIDDEN_TIMEOUT is unset the system will boot immediately. What it doesn't say is the important bit: when this feature is unset (default), the menu will be displayed, and when it is set, the menu will not be displayed.

From https://help.ubuntu.com/community/Grub2 :

"The default behavior is to hide the menu if only one operating system is present. If a user with only Ubuntu wishes to display the menu, place a # symbol at the start of this line to disable the hidden menu feature. "

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: grub2-common 1.99-21ubuntu2
ProcVersionSignature: Ubuntu 3.2.0-22.35-generic 3.2.14
Uname: Linux 3.2.0-22-generic x86_64
ApportVersion: 2.0-0ubuntu5
Architecture: amd64
Date: Wed Apr 11 15:59:04 2012
ProcEnviron:
 LANGUAGE=en_GB:en
 TERM=xterm
 PATH=(custom, user)
 LANG=en_GB.UTF-8
 SHELL=/bin/bash
SourcePackage: grub2
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Jarno Suni (jarnos)]

It is explained at 'GRUB_DEFAULT' what is the default. At least in Xenial and later the documentation states:

'GRUB_HIDDEN_TIMEOUT'
     Wait this many seconds before displaying the menu. If <ESC> is
     pressed during that time, display the menu and wait for input
     according to 'GRUB_TIMEOUT'. If a hotkey associated with a menu
     entry is pressed, boot the associated menu entry immediately. If
     the timeout expires before either of these happens, display the
     menu for the number of seconds specified in 'GRUB_TIMEOUT' before
     booting the default entry.

     If you set 'GRUB_HIDDEN_TIMEOUT', you should also set
     'GRUB_TIMEOUT=0' so that the menu is not displayed at all unless
     <ESC> is pressed.

     This option is unset by default, and is deprecated in favour of the
     less confusing 'GRUB_TIMEOUT_STYLE=countdown' or
     'GRUB_TIMEOUT_STYLE=hidden'.