Bug#850490: grub-common: Some chinese chars can't be displayed with the included unicode.pf2

[Boyuan Yang]

在 2017年8月28日星期一 CST 下午10:18:16，Boyuan Yang 写道：
> 在 2017年8月28日星期一 CST 下午8:59:10，Boyuan Yang 写道：
> 
> > Control: reopen -1 =
> > 
> > This bug is still valid and should not be closed. I am reopening it here.
> > 
> > I believe the unifont included in grub should be the root cause of the
> > bug.
> > Any further investigation would be appreciated.
> > 
> > Thanks,
> > Boyuan Yang
> 
> I got some interesting results from investigations.
> 
> If we try to locate unicode.pf2, we should get:
> 
> # locate unicode.pf2
> /boot/grub/unicode.pf2
> /boot/grub/fonts/unicode.pf2
> /usr/share/grub/unicode.pf2
> 
> It's strange that we have *two* font files in /boot/grub/. The first one has
> a size of 1.4MiB  while the second one has the size of 2.3MiB.
> 
> Here are some tests:
> 
> * Remove /boot/grub/fonts/unicode.pf2: nothing happens.
> * Remove /boot/grub/unicode.pf2: grub2 immediately fallbacks back to English
> and black-and-blue-colored theme.
> * Run "dpkg-reconfigure grub-common: /boot/grub/unicode.pf2 copied from
> /usr/ share/grub/unicode.pf2; /boot/grub/fonts/unicode.pf2 not touched.
> 
> Well now I suggests that the path /boot/grub/unicode.pf2 is a mistake and
> should not exists.
> 
> I will make further tests with fresh-installed Debian Testing in VMs later.

Some corrections and more observations:

* /boot/grub/unicode.pf2 will be (wrongly?) generated (copied) after "dpkg-
reconfigure grub-efi-amd64", not "dpkg-reconfigure grub-common".
* Grub2 in Debian Stable (Stretch) provides the *wrong* unicode.pf2 file 
(1.3MiB) while grub2 in Debian Testing/Unstable provides the good unicode.pf2 
file (2.3MiB). A stable-updates might be necessary later.

Now I believe there are two problems to be fixed in Stretch and one problem in 
Buster/Sid:

1. grub-common should provide unicode.pf2 with (somehow) better CJK character 
support (bug in Stretch only)

2. configuration in grub-efi-amd64 (and all other similar processes) may should 
install unicode.pf2 file into /boot/grub/fonts/ directory, not /boot/grub/ 
directory. (bug in both Stretch and Testing/Unstable)

Regards,
Boyuan Yang