Re: Bullets everywhere

[Kristaps Dzonsons <kristaps@bsd.lv>]

On 01/23/2011 06:22 PM, Ulrich Spoerlein wrote:
> On Sun, 23.01.2011 at 15:40:48 +0100, Ingo Schwarze wrote:
>> Hi Ulrich,
>>
>> Ulrich Spoerlein wrote on Mon, Jan 10, 2011 at 11:11:10PM +0100:
>>
>>> prompted by some gratuitous differences in groff vs mandoc output, I
>>> wanted to ask for the rationale here (if any).
>>>
>>> .Bl -bullet
>>> .It
>>> one
>>> .El
>>>
>>> will print the following raw output:
>>>
>>> mandoc:            o^Ho   one
>>> groff[1] -Tascii:  +^H+^Ho^Ho   one
>>> groff[1] -Tutf8:   ·^H·   one
>>> groff[2] -Tascii:  ^[[1m+^Ho   ^[[22mone
>>>
>>> [1] is groff 1.19.2 (the last GPLv2 release)
>>> [2] is groff 1.20.1
>>
>> We don't do -Tutf8, so that part is not relevant.
>>
>> Regarding groff-1.20.1 (which i'm using as my reference groff, too),
>> you should always use
>>
>>    /usr/local/bin/nroff -c -mandoc -Tascii
>>
>> which will produce "+\b+\bo\bo" just like groff-1.19.2 (though i
>> admit i never tried 1.19, i only use 1.15 and 1.20).
>>
>> Indeed, i have been regarding that difference as annoying for a long
>> time.  It is one of the main sources of noise in automatic comparisons,
>> so it is a real hindrance when trying to find bugs, and even worse,
>> when making sure to prevent regressions.  For example, fixing it
>> reduces the size of the /usr/src/bin diff from over 1000 to less
>> than 600 lines.
>>
>> Even if terminals capable of showing two glyphs on top of each other
>> are probably rare nowadays, so "+\b+\bo\bo" vs. "o\bo" will rarely
>> make a noticable difference for the user, i strongly feel like
>> committing the following diff, just for binary compatibility.
>>
>> At some point in the past, Kristaps voiced concerns that a similar
>> but less elegant diff i sent out might wreak havoc in the terminal
>> frontends because term.c / term_flushln() would rely on the fact
>> that backspace only occurs in the usual underline and bold sequences,
>> not as a standalone character.  Actually, this is not an issue.
>> The only guarantee needed by term_flushln() is that you don't go
>> back more than you advanced, so the diff poses no risk.
>> Besides, the diff also works fine with term.c / encode().
>> When processing "+\bo", the plus will be encoded, the backspace
>> passed through, and the circle encoded, just as we want it,
>> to produce "+\b+\bo\bo" or "_\b+\b_\bo".
>>
>> So, do you agree with this diff?
>> It survived an OpenBSD build, and the output looks good.
>
> Works for me. But there should be a small comment, explaining that this
> is for groff compat and won't do much on xterms and Co.

Please don't check this in: it causes assertions in -Tps and -Tpdf.  Let 
me look into another solution, as passing raw escapes to the backend 
makes for unhappy backends.
--
 To unsubscribe send an email to discuss+unsubscribe@mdocml.bsd.lv