[Scilab-Dev] Question about partial fix of bug #15523

[Stéphane Mottelet]

Hello devs,

As I said in http://bugzilla.scilab.org/show_bug.cgi?id=15523#c4, there 
is a an easy fix to repair mode %ODEOPTIONS(1)=2 for the "rkf" solver. 
In fact, lines 189-90 of this file

if(itask.eq.1) then iflag=1
if(itask.eq.2) then iflag=-1

appear as completely *dumb* as fortran compilers (at least gfortran on 
OSX) silently ignore the code following a "then" on the same line. The 
following program :

        program dumb_program
           flag=0
           if (flag.eq.0) then flag=1/flag
           print *,flag
        end program dumb_program

gives the output

    0.00000000

Even by using -Wall no warning is produced at compilation. Anyway, there 
are only two allowed forms:

-short form:

if (flag.eq.0) flag=1/flag

-long form:

if (flag.eq.0) then
     flag=1/flag
endif

And the fixed program works as expected

        program dumb_program
           flag=0
           if (flag.eq.0) flag=1/flag
           print *,flag
        end program dumb_program

as the output is

          Infinity

Hence, my question is: can I create a small patch for "rkf" solver, 
commited to 6.0 branch, and keep the improvements to 'rk' solver for 
master ?

S.


-- 
Stéphane Mottelet
Ingénieur de recherche
EA 4297 Transformations Intégrées de la Matière Renouvelable
Département Génie des Procédés Industriels
Sorbonne Universités - Université de Technologie de Compiègne
CS 60319, 60203 Compiègne cedex
Tel : +33(0)344234688
http://www.utc.fr/~mottelet