poor line numbering in error messages when using unwind_protect

[John W. Eaton]

On  1-Feb-2009, Søren Hauberg wrote:

| Hi
| 
| Consider the following function (also attached)
| 
|   function badlinenumber ()
|     unwind_protect
|       error ("this raises and error at line 3");
|     unwind_protect_cleanup
|     end_unwind_protect
|   endfunction
| 
| When I run it I get the following error message
| 
|   error: this raises and error at line 3
|   error: called from:
|   error:   /home/sh/Skrivebord/badlinenumber.m at line 2, column 3
| 
| I would expect the last line to say "line 3, ..." instead of "line
| 2, ...".
| 
| I see something similar with try-catch statements. Consider (also
| attached)
| 
|   function badlinenumber2 ()
|     try
|       error ("this raises and error at line 3");
|     catch
|       disp (lasterror ()(1).stack.line);
|     end_try_catch
|   endfunction
| 
| When I call this function I get '2' where I would expect '3'.
| 
| Now that I'm testing this I see the same issue with 'for' loops,
| 
|   function badlinenumber3 ()
|     for k = 1:10
|       error ("this raises and error at line 3");
|     endfor
|   endfunction
| 
| which once again gives me an error at line 2 instead of 3.

I checked in the following changeset, which seems to fix the problem
for me.

  http://hg.savannah.gnu.org/hgweb/octave/rev/33783e94fb16

Thanks,

jwe