[tex-k] Uninterruptible loop in web2c TeX

[Reinhard Kotucha]

On 2020-08-20 at 08:40:54 +0700, Igor Liferenko wrote:

 > Hi Reinhard ,
 >
 > > after pressing Ctrl+C, did you do what the message said?
 >
 > Here is the full transcript:
 >
 > $ tex
 > This is TeX, Version 3.14159265 (TeX Live 2020/Debian) (preloaded format=tex)
 > **\relax
 >
 > *^C! Interruption.
 > <*>
 >
 > ? (Please type a command or say `\end')
 > *(Please type a command or say `\end')
 > *(Please type a command or say `\end')
 > *(Please type a command or say `\end')
 > <ad infinitum>
 >
 > >  Did you enter "\end"?
 >
 > It does not allow me to enter `\end' because it seems it always reads
 > EOF from stdin.
 >
 > > Please try
 > >
 > >   1) run `tex'
 > >   2) type `\relax' and <return>
 > >   3) press Ctrl+C
 > >   4) type \end
 > >
 > > Does this work?
 >
 > It is not supposed to work, because after Ctrl+C I get the `?' prompt,
 > and `\end' can be entered only in `*' prompt.

But if you press <return> you get the message

  (Please type a command or say `\end')

and you can abort with \end.

Regards,
  Reinhard

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Reinhard Kotucha                            Phone: +49-511-3373112
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