Re: Demystifying “symbol” fonts

[toki]

On 17/11/2016 12:00, Khaled Hosny wrote:

> The bullets in the bug document use the “Symbol” font from Windows,
> which has “symbol” cmap subtable that maps characters from Private Use
> Area to its own glyphs. Because the document uses PUA symbols, without

Anything in the PUA is up for grabs.

If using glyphs from the PUA, the only safe assumption is that the
reader will see Tofu.

MUFI, CSUR, and UCSUR are very careful to point out that the code points
the writing systems within their specific registry, can clash with each
other writing systems within their specific registry, as well as with
writing systems from other organizations that have set up PUA registries.

Those organizations also point out that when using writing systems
within their specific registry, one also needs to use the font they
recommend for the specific writing system.

For bullets, you should be using glyphs in the code point range Ux2600
through Ux27BF and/or Ux1F300 through Ux1F67F. (OK, there are couple of
other ranges that have nice glyphs to use as bullets. My point is that
there is no legitimate reason to use PUA glyphs as bullets. That LibO
does not correctly handle some of the glyphs in the Ux1F6## range is a
separate issue.)

> so my question is what is the expected behaviour here, map the PUA to proper Unicode characters? Expect the font or a compatible one to be installed and usable? Bundle a compatible font?

If the original font is embedded in the document, then the expected
behaviour is to display the glyph in question.

If the original font is not embedded in the document, then the expected
behaviour is to display Tofu.

jonathon

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