Re: Unacceptable size increase to ALL live images in F28: Noto CJK Fonts

[Stephen Gallagher]

On Thu, Mar 29, 2018 at 10:12 AM Kevin Kofler <kevin.kofler(a)chello.at&gt;
wrote:

>  Hi,
>
>  we did more debugging on #fedora-kde (thanks in particular to lupinix) and
>  we found what seems to be the primary source of the bloat: CJK fonts!
>
>  CJK fonts are by far the largest of all fonts due to the huge number of
>  characters used in those languages.
>
>  Up to Fedora 26, Fedora shipped 4 CJK fonts:
>        <packagereq
>  type="default">adobe-source-han-sans-cn-fonts</packagereq>
>        <packagereq
>  type="default">adobe-source-han-sans-tw-fonts</packagereq>
>        <packagereq
> type="default">naver-nanum-gothic-fonts</packagereq>
>        <packagereq type="default">vlgothic-fonts</packagereq>
>  The KDE and LXQt Spins actually opted to blacklist these fonts in their
>  kickstart, and ship one compact CJK font instead: wqy-microhei-fonts.
>
>  In Fedora 27, this Change:
>  https://fedoraproject.org/wiki/Changes/ChineseSerifFonts
>  added 2 additional fonts (for a total of 6):
>        <packagereq
>  type="default">adobe-source-han-serif-cn-fonts</packagereq>
>        <packagereq
>  type="default">adobe-source-han-serif-tw-fonts</packagereq>
>  which were unfortunately missing from the blacklist:
>  https://bugzilla.redhat.com/show_bug.cgi?id=1530006
>  already increasing the size of the image.
>
>  But now in Fedora 28, after:
>  https://fedoraproject.org/wiki/Changes/JPDefaultFontsToNoto
>  https://fedoraproject.org/wiki/Changes/KRDefaultFontsToNoto
>  https://fedoraproject.org/wiki/Changes/ChineseDefaultFontsToNoto
>  we actually ship a whopping 12 CJK fonts:
>        <packagereq
> type="default">google-noto-sans-jp-fonts</packagereq>
>        <packagereq
> type="default">google-noto-sans-kr-fonts</packagereq>
>        <packagereq
>  type="default">google-noto-sans-mono-cjk-jp-fonts</packagereq>
>        <packagereq
>  type="default">google-noto-sans-mono-cjk-kr-fonts</packagereq>
>        <packagereq
>  type="default">google-noto-sans-mono-cjk-sc-fonts</packagereq>
>        <packagereq
>  type="default">google-noto-sans-mono-cjk-tc-fonts</packagereq>
>        <packagereq
> type="default">google-noto-sans-sc-fonts</packagereq>
>        <packagereq
> type="default">google-noto-sans-tc-fonts</packagereq>
>        <packagereq
> type="default">google-noto-serif-jp-fonts</packagereq>
>        <packagereq
> type="default">google-noto-serif-kr-fonts</packagereq>
>        <packagereq
> type="default">google-noto-serif-sc-fonts</packagereq>
>        <packagereq
> type="default">google-noto-serif-tc-fonts</packagereq>
>  none of which are blacklisted in the Spins! According to lupinix, these
>  amount to a download size (and thus an xz-compressed size, which is also
>  the
>  compression algorithm used for the live images) of 364 MiB!
>
>  The fix is to update the blacklists in the KDE and LXQt spin kickstarts, as
>  per the discussion under:
>  https://bugzilla.redhat.com/show_bug.cgi?id=1530006
>  IMHO, this needs to be implemented, urgently.
>
>  But I think we also need to generally consider whether it makes sense to
>  force 3 font variants for each CJK language on all users worldwide, and
>  whether there are smaller fonts that could be used. (E.g.,
>  wqy-microhei-fonts is very effective, but unfortunately it only covers
>  Simplified Chinese and the syllabic parts of Japanese and Korean, not the
>  Traditional Chinese, Japanese or Korean renderings of the CJK Unified
>  Ideographs.)
>
>  
Kevin, thanks for the investigation and the detailed analysis. Great work
tracking this down!

I think our font strategy is a bit complicated, because we do strive to be
an international distribution, but I feel like there must be better ways to
accomplish this goal than to simply install all possible fonts by default.
I know that for GNOME at least, there's some PackageKit integration that
allows users to be prompted to install fonts as-needed (though it also
seems to trigger whenever I accidentally `cat` a binary file in the
terminal :-) ). Perhaps we can look into finding a desktop-agnostic way of
doing this and then limit our installed fonts to only a few minimal ones
based on the language selected in Anaconda?