Re: [Dev-luatex] Possible double use of inserts

5 Apr 2023

      The code (and error messages) you are showing are from latex  not from the
luatex engine.
so should be reported https://github.com/latex3/latex2e/issues not here

If you stress \newinsert that much, as documented in source2e.pdf
(ltplain.dtx)
it will shuffle some float box allocations around but it does look like it
does not
correctly trap the end condition. Other engines (even when they have e-tex
extended
registers) count down from 255 for \newinsert. so get to 0 without any
complication
around legacy use of 255. lualatex is counting down from a few thousand.

In practice latex doesn't use insert much (it only uses two inserts by
default) so apart from
test cases this seems unlikely to ever occur in practice but we should
probably fix.

At least I suspect a fix is needed, I haven't fully traced what your log is
showing yet.

David

On Wed, 5 Apr 2023 at 07:54, Martin Münch  wrote:
...
May the file LuaInsert.tex consist of
\documentclass{minimal}
\makeatletter
\newcommand{\stressInsert}[1]{%
  \@tempcnta=0\relax%
  \@whilenum\the\@tempcnta<#1\do%
   {\advance\@tempcnta +1\relax%
    \expandafter\newinsert\csname TestInsert\the\@tempcnta\endcsname%
    \message{insert \the\@tempcnta: \the\allocationnumber^^J}%
   }%
  }
\makeatother
\stressInsert{70000}
\begin{document}
\end{document}
then
...
lualatex LuaInsert.tex
creates LuaInsert.log, which also contains:
This is LuaHBTeX, Version 1.16.0 (TeX Live 2023)  (format=lualatex
2023.4.4)
...
\TestInsert1=\insert199
  insert 1: 199
\TestInsert2=\insert198
insert 2: 198
...
\TestInsert17=\insert183
insert 17: 183
                              [ *** 1st JUMP HERE *** ]
\TestInsert18=\insert252
insert 18: 252
\TestInsert19=\insert251
insert 19: 251
...
\TestInsert68=\insert202
insert 68: 202
\TestInsert69=\insert201
insert 69: 201
                              [ *** 2nd JUMP HERE *** ]
\TestInsert70=\insert65534
insert 70: 65534
\TestInsert71=\insert65533
insert 71: 65533
...
\TestInsert65350=\insert254
insert 65350: 254
\TestInsert65351=\insert253
insert 65351: 253
\TestInsert65352=\insert252 [ *** AGAIN?! ***]
insert 65352: 252
\TestInsert65353=\insert251 [ *** AGAIN?! ***]
insert 65353: 251
...
\TestInsert65368=\insert236 [ *** AGAIN?! ***]
insert 65368: 236
\TestInsert65369=\insert235 [ *** AGAIN?! ***]
insert 65369: 235
! No room for a new \count .
\ch@ck ...\else \errmessage {No room for a new #3}
                                                   \fi
l.12 \stressInsert{70000}
? x
So, are \insert252 to \insert235 used twice?!
And Lua does not even stop there because of "No room for a new insert",
but because there is no room for a new \count! Otherwise more inserts
would see double use?
Should after \insert253 (!, not 235) the next \newinsert produce some
error "No room for a new \insert"?
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Re: [Dev-luatex] Possible double use of inserts

David Carlisle