NOTE: I use _ to represent U+00AD, the conditional hyphen.

In my css I have
body { hyphens:auto; }

<https://drafts.csswg.org/css-text/#valdef-hyphens-auto> says
"Automatic hyphenation opportunities elsewhere WITHIN A WORD must be
ignored if the word contains a conditional hyphen. ... [emphasis
added]"

I don't know whether "within a word" is meant to include placing a
conditional hyphen immediately before the first character of a word.
If it is, that would make that word automatically hyphens:none, and
one character is obviously shorter than <span class="..."> ...
</span>

Firefox (for several years now) does treat a leading conditional
hyphen that way, and doesn't auto-hyphenate the word. For instance,
"personal" breaks as "per- sonal"
"_personal" goes to the next line as "personal"
"person_al" goes to the next line as "personal"

Chrome (the current version), however, just ignores the leading
conditional hyphen though it does follow the spec for a conditional
hyphen somewhere between the first and last characters of the word.
For instance,
"personal" breaks as "per- sonal"
"_personal" breaks as "per- sonal"
"person_al" goes to the next line as "personal"

Is Chrome wrong here, or is a leading conditional hyphen not within
the meaning of "Within a word" and UAs get to make up their own
minds?

(For those who may be wondering, the documents I'm preparing are not
on the Web, but have a restricted audience where I can be sure that
everyone's PC has the font I specify, and it's not important if they
don't see hyphenation on their phones.)

--
Stan Brown, Tehachapi, California, USA
https://BrownMath.com/

Presumably this hasn't been answered because no one knows the answer,
or the ones who do are uninterested in the topic. But I'm just giving
it one more shot, in case a knowledgeable and interested person just
happened not to see it.

On Sun, 17 Dec 2023 11:47:52 -0800, Stan Brown wrote:
>
> NOTE: I use _ to represent U+00AD, the conditional hyphen.
>
> In my css I have
> body { hyphens:auto; }
>
> <https://drafts.csswg.org/css-text/#valdef-hyphens-auto> says
> "Automatic hyphenation opportunities elsewhere WITHIN A WORD must be
> ignored if the word contains a conditional hyphen. ... [emphasis
> added]"
>
> I don't know whether "within a word" is meant to include placing a
> conditional hyphen immediately before the first character of a word.
> If it is, that would make that word automatically hyphens:none, and
> one character is obviously shorter than <span class="..."> ...
> </span>
>
> Firefox (for several years now) does treat a leading conditional
> hyphen that way, and doesn't auto-hyphenate the word. For instance,
> "personal" breaks as "per- sonal"
> "_personal" goes to the next line as "personal"
> "person_al" goes to the next line as "personal"
>
> Chrome (the current version), however, just ignores the leading
> conditional hyphen though it does follow the spec for a conditional
> hyphen somewhere between the first and last characters of the word.
> For instance,
> "personal" breaks as "per- sonal"
> "_personal" breaks as "per- sonal"
> "person_al" goes to the next line as "personal"
>
> Is Chrome wrong here, or is a leading conditional hyphen not within
> the meaning of "Within a word" and UAs get to make up their own
> minds?
>
> (For those who may be wondering, the documents I'm preparing are not
> on the Web, but have a restricted audience where I can be sure that
> everyone's PC has the font I specify, and it's not important if they
> don't see hyphenation on their phones.)

--
Stan Brown, Tehachapi, California, USA
https://BrownMath.com/