Re: error: terminal: >> NOfTextColumns-1, ! Improper final value has been replaced by 0

[Hans Hagen <pragma@wxs.nl>]

On 4/24/2013 5:30 PM, Lars Huttar wrote:
> Hello,
>
> I'm encountering the following error, under ConTeXt  ver: 2012.05.30
> 11:26 MKIV  fmt: 2013.3.11  int: english/english:
>
> system > tex > error on line 27 in file
> data/three-volume-book-book-1.tex: terminal: >> NOfTextColumns-1
> ! Improper final value has been replaced by 0.
> <to be read again>
>                     :
> <*> for i=1 upto NOfTextColumns-1:
>                                      draw (rightboundary TextColumns[i])
> shif...
>
>
>   ...
>
> 17 \safeinput ./data/statistics-for-area-area-africa.tex
> 18 \safeinput ./data/statistics-for-area-area-europe.tex
> 19
> 20
> 21
> 22 \input ./macros/E16pagenohead.tex
> 23 \ifodd \pageno \else \noheaderandfooterlines \null \page[yes]\fi
> \noheade
> randfooterlines
> 24
> 25 \startptp{
> 26 \pagereference[Languages]\pnum{Part II}\ptitle{Language Listings}
> 27 >> }\stopptp
>
>
> This error is very odd because:
>
> a) The only place I can find code mentioning "NOfTextColumns-1" is in
> mp-core.mpii, where it's commented out!
>    % \startuseMPgraphic{whatever}
>    %     for i=1 upto NOfTextColumns-1 :
>    %         draw (rightboundary TextColumns[i]) shifted ...
>
> But maybe I just haven't been looking in the right places.
>
> b) The place in my .tex document where the error occurs, line 27, is at
> a \stopptp. Yet there is an essentially identical start/stopptp earlier
> in the document, where no such error is thrown:
>
>    \startptp{
>    \pagereference[Summaries]\pnum{Part I}\ptitle{Statistical Summaries}
>    }\stopptp
>
> So I guess there's some content in between the two starts/stop ptp's
> that's laying the stage for the error to occur.
> I'll be working on a minimal example, but that's time-consuming; and I
> thought in the meantime, there may be some clues in the above
> information that could help clarify the nature of the problem, to
> someone who understands the inner workings of ConTeXt.

It took me a while to figure it out as NOfTextColumns is only used in 
very special cases and long gone from context (it dates from a previous 
background implementation). Normally the obsolete code is never seen but 
in your case consulting the variable might be triggered by the fact that

multi_column_first_page_hack

is set to true (looks like a quick hack i made for Jelle long ago).

I commented it in the mkii source now, hopefully no error message any 
longer.

Hans

ps. sometimes there is some specific test code that then depends on 
other experimental code being present

ps. in mkiv it's all redone anyway and i will redo columnsets one of 
these days too;


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                                           Hans Hagen | PRAGMA ADE
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