Bug 152464 - Latex freezes
Summary: Latex freezes
Keywords:
Status: CLOSED NOTABUG
Alias: None
Product: Fedora
Classification: Fedora
Component: tetex
Version: 3
Hardware: i686
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Jindrich Novy
QA Contact: David Lawrence
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2005-03-29 18:57 UTC by PE Meunier
Modified: 2013-07-02 23:06 UTC (History)
1 user (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed: 2005-04-18 09:32:53 UTC
Type: ---
Embargoed:


Attachments (Terms of Use)

Description PE Meunier 2005-03-29 18:57:54 UTC
Not really severe, but quite unpleasant when you dont know why it freezes.
When using LaTeX, having done (by mistake) a recursive new command, latex doesnt
detect it, and tries to finish the job anyway, which causes it to freeze.
Example :
\documentclass{article}
\newcommand\vect{\vect}
\begin{document}
\end{document}

I know, I should have done the following, but that's a bug anyway :

\documentclass{article}
\newcommand\vect{\overrightarrow}
\begin{document}
\end{document}

Comment 1 Jindrich Novy 2005-03-30 06:37:42 UTC
PE, this looks like a feature request to the original LaTeX maintainers than a
bug that needs to fixed for FC3 teTeX. Could you please report this problem
upstream?

Read first:
http://www.latex-project.org/bugs.html

and then please file the bug in:
http://www.latex-project.org/bugs-upload.html

Could you then add here a reference to the bug you reported so that I can track it?

Thanks,
Jindrich

Comment 2 Jindrich Novy 2005-04-18 09:32:53 UTC
I reported it upstream myself. It has the internal identification `latex/3776'.

Comment 3 Jindrich Novy 2005-04-18 11:15:28 UTC
Upstream developer responded:

This is also known as the halting problem. The TeX engine -- and therefore  
also LaTeX -- is Turing complete and it is a proven fact that a Turing  
Machine cannot determine in advance that something will cause an infinite  
loop. It can only be done by executing it and hoping for the best.

The good thing about computers being so fast these days is that when you  
observe LaTeX hanging for a few seconds there is a good chance it's  
because you accidentally caused it to go into an infinite loop. There are  
many ways to get LaTeX into an infinite loop and the indispensable The  
LaTeX Companion 2nd edition has several examples on that topic.


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