From bug-octave-request at bevo dot che dot wisc dot edu  Mon Mar 30 23:44:00 1998
Subject: A bug with errors in functions dying silently
From: "John W. Eaton" <jwe at bevo dot che dot wisc dot edu>
To: Francesco Potorti` <F dot Potorti at cnuce dot cnr dot it>
Cc: bug-octave at bevo dot che dot wisc dot edu
Date: Mon, 30 Mar 1998 23:43:56 -0600 (CST)

On 30-Mar-1998, Francesco Potorti` <F dot Potorti at cnuce dot cnr dot it> wrote:

: Bug report for Octave 2.0.11 configured for i386-pc-linux-gnu
: 
: Description:
: -----------
: 
: Some errors inside a function stop the execution of the function with
: no error message

That's because your error happens inside a try/catch block, which is
designed to suppress errors like this.  If your code ends up in the
catch section of the try/catch block, an error occurred, and you can
access the message in the built-in variable __error_text__.

:   save_prefer_column_vectors = prefer_column_vectors;
:   try
:     prefer_column_vectors = 0;
:     ...
:   catch
:     prefer_column_vectors = save_prefer_column_vectors;
:   end_try_catch

I think what you really want to use for this is unwind_protect, not
try/catch.

jwe