[Dev-luatex] Re: missing displacement when leqno is used in rtl paragraph

On Sat, 1 Feb 2025 at 17:18, Udicoudco wrote:

On Sat, Feb 1, 2025 at 4:24 PM Ulrike Fischer wrote:

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Am Sat, 1 Feb 2025 14:41:57 +0100 schrieb Hans Hagen:

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You can best try to handle this at the macro level. Page direction can badly interfere anyway and every change we make to the diretion code will introduce another issue. Just don't use it. FWIW, in luametatex we don't even have \pagedirection any more.

I came to the same conclusion after doing a number of tests (in

https://github.com/LaTeX-Package-Repositories/geometry/issues/20#issuecommen... )

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where my summary was "As you want 'left margin' to mean 'left margin' imho the correct way to handle this not to set these directions at all. It looks wrong to change all reference points and then to add lots of complicated calculations to get the old behaviour back."

I was probably rambling too much :) In practice there is only one bad case left, which could be fixed like the other cases:

\catcode`\{=1\catcode`\}=2\catcode`\$=3 \directlua{tex.enableprimitives("",{"Umathquad", "mathdirection", "predisplaydirection", "pagedirection", "bodydirection"})}

\font\tenrm=cmr10 \textfont0=\tenrm\textfont1=\tenrm \tenrm \hsize=345pt\vsize=550pt\parfillskip=0.0pt plus 1.0fil \parindent=15pt\parskip=0pt plus1pt \Umathquad\textstyle=10pt

\mathdirection1 (l)=false swapdir=true mathdir=TRT $$\predisplaydirection=-1 1 \leqno(1)$$

\pagedirection=1\bodydirection=1 \end

but as you suggested' I'm trying to avoid the usage of \pagedirection and \bodydirection, so I don't have a strong opinion if it should be fixed or not.

I attached another patch. *Most Importantly* this patch also amends the last one, as I did not consider correctly some cases in a situation where the equation number is "too close".

If you don't want to fix this last case, I'll send a patch which only fixes the last commit.

I apply the patch on gitlab-lisn but I wait to upload it to texlive; if there are problems we will decide the final version. -- luigi