Hello,
I think that displacement of a the of a math display
is missing when \leqno is used in RTL paragraph.
I attached a patch. Here is a simple test code (it requires the cmr10 font):
\catcode`\{=1\catcode`\}=2\catcode`\$=3
\directlua{tex.enableprimitives("",{"pardirection", "textdirection",
"Umathquad"})}
\tracingoutput=1\tracingonline=1
\showboxbreadth 16384 \showboxdepth 16384
\font\tenrm=cmr10
\textfont0=\tenrm
\hsize=345pt\vsize=550pt\parfillskip=0.0pt plus 1.0fil
\parindent=15pt\parskip=0pt plus1pt
\Umathquad\textstyle=10pt
\pardirection=1\textdirection=1
$$1 \leqno(1)$$
\end
Udi
