[v3,8/8] package/petitboot: prefer UTF-8 support

The petitboot UI looks much nicer in a Unicode locale:

* Items in the language selection submenu use multibyte Unicode
  characters. In other locales, they say "Unable to display text in this
  locale".

* The combination of TERM=linux with a UTF-8 locale is required to
  trigger a special-case workaround in ncurses code[1]. Without
  this, line-drawing characters in the menu look like q's.

Add a reminder that a UTF-8 locale should be generated for things to
look right. Assume C.UTF-8 by default, allowing $LANG to be overridden
(by /etc/default/petitboot or otherwise) if something else is desired.

[1] https://invisible-island.net/ncurses/ncurses.faq.html#no_line_drawing

Signed-off-by: Reza Arbab <arbab@linux.ibm.com>
---
 package/petitboot/Config.in      | 8 ++++++--
 package/petitboot/S15pb-discover | 1 +
 package/petitboot/pb-console     | 1 +
 package/petitboot/shell_profile  | 3 +++
 4 files changed, 11 insertions(+), 2 deletions(-)

On 09/10/2023 17:17, Reza Arbab wrote:
> The petitboot UI looks much nicer in a Unicode locale:
> 
> * Items in the language selection submenu use multibyte Unicode
>    characters. In other locales, they say "Unable to display text in this
>    locale".
> 
> * The combination of TERM=linux with a UTF-8 locale is required to
>    trigger a special-case workaround in ncurses code[1]. Without
>    this, line-drawing characters in the menu look like q's.
> 
> Add a reminder that a UTF-8 locale should be generated for things to
> look right. Assume C.UTF-8 by default, allowing $LANG to be overridden
> (by /etc/default/petitboot or otherwise) if something else is desired.

  So, this improves things, but they're not really necessary. I think it's 
better then to just put in the help text that it looks better with UTF-8 locale 
enabled.

> 
> [1] https://invisible-island.net/ncurses/ncurses.faq.html#no_line_drawing
> 
> Signed-off-by: Reza Arbab <arbab@linux.ibm.com>
> ---
>   package/petitboot/Config.in      | 8 ++++++--
>   package/petitboot/S15pb-discover | 1 +
>   package/petitboot/pb-console     | 1 +
>   package/petitboot/shell_profile  | 3 +++
>   4 files changed, 11 insertions(+), 2 deletions(-)
> 
> diff --git a/package/petitboot/Config.in b/package/petitboot/Config.in
> index 0f965e71e628..a449ed87872c 100644
> --- a/package/petitboot/Config.in
> +++ b/package/petitboot/Config.in
> @@ -4,6 +4,7 @@ config BR2_PACKAGE_PETITBOOT
>   	depends on BR2_PACKAGE_KEXEC_ARCH_SUPPORTS
>   	depends on BR2_USE_MMU # lvm2
>   	depends on BR2_USE_WCHAR # elfutils
> +	depends on BR2_ENABLE_LOCALE
>   	depends on !BR2_STATIC_LIBS # elfutils, lvm2
>   	depends on BR2_TOOLCHAIN_HAS_THREADS # elfutils, lvm2
>   	depends on BR2_TOOLCHAIN_USES_UCLIBC || BR2_TOOLCHAIN_USES_GLIBC # elfutils
> @@ -11,6 +12,7 @@ config BR2_PACKAGE_PETITBOOT
>   	select BR2_PACKAGE_ELFUTILS
>   	select BR2_PACKAGE_LVM2 # devmapper
>   	select BR2_PACKAGE_NCURSES
> +	select BR2_PACKAGE_NCURSES_WCHAR
>   	# run-time dependencies
>   	select BR2_PACKAGE_KEXEC if !BR2_PACKAGE_KEXEC_LITE
>   	select BR2_PACKAGE_KEXEC_LITE if ( BR2_powerpc || BR2_powerpc64 || BR2_powerpc64le )
> @@ -20,12 +22,14 @@ config BR2_PACKAGE_PETITBOOT
>   	help
>   	  Petitboot is a small kexec-based bootloader
>   
> +	  NOTE: petitboot needs a working UTF-8 locale (BR2_GENERATE_LOCALE)
> +
>   	  http://www.kernel.org/pub/linux/kernel/people/geoff/petitboot/petitboot.html
>   
> -comment "petitboot needs a uClibc or glibc toolchain w/ wchar, dynamic library, threads, udev /dev management"
> +comment "petitboot needs a uClibc or glibc toolchain w/ wchar, locale, dynamic library, threads, udev /dev management"
>   	depends on BR2_PACKAGE_KEXEC_ARCH_SUPPORTS
>   	depends on BR2_USE_MMU
> -	depends on !BR2_USE_WCHAR || BR2_STATIC_LIBS || \
> +	depends on !BR2_USE_WCHAR || !BR2_ENABLE_LOCALE || BR2_STATIC_LIBS || \
>   		!BR2_TOOLCHAIN_HAS_THREADS || \
>   		!(BR2_TOOLCHAIN_USES_UCLIBC || BR2_TOOLCHAIN_USES_GLIBC) || \
>   		!BR2_PACKAGE_HAS_UDEV
> diff --git a/package/petitboot/S15pb-discover b/package/petitboot/S15pb-discover
> index a37e33521f1a..15b428ce0e42 100644
> --- a/package/petitboot/S15pb-discover
> +++ b/package/petitboot/S15pb-discover
> @@ -15,6 +15,7 @@ start() {
>   	# shellcheck disable=SC2174 # only apply -m to deepest dir
>   	mkdir -p -m 0775 /var/log/petitboot
>   	chown root:petitgroup /var/log/petitboot
> +	export LANG="${LANG:-C.UTF-8}"

  I think it's better to rely on the default locale being set to C.UTF-8. Hm, it 
seems we don't actually set a default locale though... Perhaps we should add a 
system menu entry to do exactly that. Though I'm not sure if it's even possible 
with uClibc (glibc has /etc/locale.conf).

  Regards,
  Arnout

>   
>   	# shellcheck disable=SC2086 # we need the word splitting
>   	start-stop-daemon -S -q -b -m -p "$PIDFILE" -x "/usr/sbin/$DAEMON" \
> diff --git a/package/petitboot/pb-console b/package/petitboot/pb-console
> index eea40163d02f..55e5462f0457 100644
> --- a/package/petitboot/pb-console
> +++ b/package/petitboot/pb-console
> @@ -13,6 +13,7 @@ start() {
>   	# shellcheck disable=SC2174 # only apply -m to deepest dir
>   	mkdir -p -m 0775 /var/log/petitboot
>   	chown root:petitgroup /var/log/petitboot
> +	export LANG="${LANG:-C.UTF-8}"
>   
>   	# shellcheck disable=SC2086 # we need the word splitting
>   	start-stop-daemon -S -q -x "/usr/libexec/petitboot/$DAEMON" \
> diff --git a/package/petitboot/shell_profile b/package/petitboot/shell_profile
> index 1ca5e6364dba..6bbe49e6d113 100644
> --- a/package/petitboot/shell_profile
> +++ b/package/petitboot/shell_profile
> @@ -1,2 +1,5 @@
> +[ -r "/etc/default/petitboot" ] && . "/etc/default/petitboot"
>   export ENV="/home/petituser/.shrc"
> +export LANG="${LANG:-C.UTF-8}"
> +
>   exec /usr/libexec/petitboot/pb-console

On Sun, Nov 05, 2023 at 07:30:28PM +0100, Arnout Vandecappelle wrote:
>On 09/10/2023 17:17, Reza Arbab wrote:
>>Add a reminder that a UTF-8 locale should be generated for things to
>>look right. Assume C.UTF-8 by default, allowing $LANG to be overridden
>>(by /etc/default/petitboot or otherwise) if something else is desired.
>
> So, this improves things, but they're not really necessary. I think 
>it's better then to just put in the help text that it looks better 
>with UTF-8 locale enabled.

Will change.

>>--- a/package/petitboot/S15pb-discover
>>+++ b/package/petitboot/S15pb-discover
>>@@ -15,6 +15,7 @@ start() {
>>  	# shellcheck disable=SC2174 # only apply -m to deepest dir
>>  	mkdir -p -m 0775 /var/log/petitboot
>>  	chown root:petitgroup /var/log/petitboot
>>+	export LANG="${LANG:-C.UTF-8}"
>
> I think it's better to rely on the default locale being set to 
>C.UTF-8. Hm, it seems we don't actually set a default locale though... 
>Perhaps we should add a system menu entry to do exactly that. Though 
>I'm not sure if it's even possible with uClibc (glibc has 
>/etc/locale.conf).

No problem, I'll take this out. I think we can defer to the user to set 
a UTF-8 system locale. A config option for default locale would be nice 
indeed.