Bug#169040: tetex-bin: tex uses "empty" filename after first "another file" request on input error

[Olaf Weber <olaf@infovore.xs4all.nl>]

Michael L Brownlow writes:

> Example session:
> ~/tex$ tex
> This is TeX, Version 3.14159 (Web2C 7.3.7)
> **sorry
> ! I can't find file `sorry'.
> <*> sorry
         
> Please type another input file name: 
> (/usr/share/texmf/tex/latex/tools/.tex File ignored)
> *\end
> No pages of output.
> Transcript written on .log.
> ~/tex$

> At the "Please type another input file name" prompt, end-of-line was
> sent.

> According to The TeXbook, the behavior should be to ask for another
> input file name until a real file is found. (p.30-31, Experiment (not
> exercise) 5)

A real file was found: /usr/share/texmf/tex/latex/tools/.tex

This is deliberately provided by latex2e, in the tools package.
Consider the following from fileerr.dtx:

% \section{Introduction}
%    When \LaTeXe{} is unable to find a file it will ask for an
%    alternative file name. However, sometimes the problem is
%    only noticed by \TeX{}, and in that case \TeX{} insists on
%    getting a valid file name; any other attempt to leave this
%    error loop will fail.\footnote{On some systems, \TeX{}
%    accepts a special character denoting the end of file to
%    return from this loop, e.g.\ Control-D on UNIX or Control-Z
%    on DOS.} Many users try to respond in the same way as to
%    normal error messages, e.g.\ by typing \meta{return}, or |s|
%    or |x|, but \TeX{} will interpret this as a file name and
%    will ask again.
%    \par To provide a graceful exit out of this loop, we define
%    a number of files which emulate the normal behavior of
%    \TeX{} in the error loop as far as possible.
%    \par After installing these files the user can respond with
%    |h|,  |q|, |r|, |s|, |e|, |x|, and on some systems also with
%    \meta{return} to \TeX's missing file name question.


-- 
Olaf Weber

               (This space left blank for technical reasons.)