[NTG-context] LMTX incompatibility in \meaning breaks TikZ, other minor issues

[Hans Hagen]

On 9/22/2022 2:23 PM, Leah Neukirchen via ntg-context wrote:
> Hi,
> 
> I'm trying to get tikz-cd to run on LMTX and some examples already
> work fine, but I had a problem with text on arrows.
> 
> To reproduce:
> 
> \usemodule[tikz]
> \usetikzlibrary[cd]
> 
> \starttext
> \starttikzcd
> A \arrow{r}{A} \NC B \NR
> \stoptikzcd
> \stoptext
> 
> This builds fine on MkIV from TeXLive 2022 with LuaTeX, but on LMTX I get:
> 
> system          > ConTeXt  ver: 2022.09.11 20:44 LMTX  fmt: 2022.9.20  int: english/english
> ...
> close source    > level 2, order 63, name 'tikzlibrarycd.code.tex'
> fonts           > preloading latin modern fonts (second stage)
> fonts           > 'fallback modern-designsize rm 12pt' is loaded
> tex error       > tex error on line 8 in file ./tik.tex: Package pgfkeys Error: I do not know the key '/tikz/"{A}"{}' and I am going to ignore it. Perhaps you misspelled it.^^J...^^Jl.7 I think the culprit is a tikzcd arrow in cell 1-1
> 
> After a bunch of debugging, it turns out that LMTX breaks the TikZ 'quotes'
> library, which works using code ala:
> 
> \def\tikz at enable@node at quotes{%
>    \pgfkeyssetvalue{/handlers/first char syntax/the character "}{\tikz at quote@parser}%
>    \let\tikz at quotes@as\tikz at node@quotes at as%
> }
> 
> The last part of the /-key is derived from \meaning, but in LMTX,
> \meaning" is "the character U+0022 'quotation mark'"
> and thus the key cannot be found.
> 
> I have patched TikZ for now to match for this alternate string too.

a bit weird way to test a key .. maybe you can compare to

\edef\ThatQuote{\meaning/}

using \ifx

> But perhaps it would be better for compatibility to agree with the
> original TeX \meaning strings for the 7-bit ASCII subset at least. 

too messy when want to parse

> I found another minor nit that's not really triggering a bug but still a
> difference to LuaTeX: \eTeXrevision should expand to .2, but it
> expands to 2 in MkIX.  There is some code out there which uses
> constructions like
> \number\eTeXversion\eTeXrevision
> or even
> \ifdim 0\XeTeXrevision pt > 0.9996pt
> 
> As LMTX doesn't care about this macro, this should be easy to adjust.
i'll add the period; btw afaikt testing for an etex version is useless 
because all used engines have it and there is basically only one version 
and there will be no follow ups

Hans

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                                           Hans Hagen | PRAGMA ADE
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