[Octave-bug-tracker] [bug #30514] Array indexing error?

[Jaroslav Hajek]

Update of bug #30514 (project octave):

                Category:                    None => Interpreter            
                  Status:                    None => Fixed                  
             Assigned to:                    None => highegg                
             Open/Closed:                    Open => Closed                 

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Follow-up Comment #1:

The crashes after the out-of-memory error are probably Windows-specific,
because I don't see them on Linux neither in 3.3.51+ nor 3.2.4. Most likely
related to some OctaveForge packages.


The out-of-memory itself is a bug in a workaround for LAPACK's bug in
workspace query. The dependence on number of rows is caused by integer
overflows. Indexing has nothing to do with this.


John, apparently it was you who introduced it with 7486:6a6d2abe51ff for some
reason, so I invite you to take a look at my fix:
http://hg.savannah.gnu.org/hgweb/octave/rev/2c2d4a2f1047

I think the workaround needs only be triggered when both n > m and n >=
mnthrs, because that's the only case when the following block from dgelsd in
lapack 3.2 is met:

!     XXX: Ensure the Path 2a case below is triggered.  The workspace
!     calculation should use queries for all routines eventually.
               MAXWRK = MAX( MAXWRK,
     $              4*M+M*M+MAX( M, 2*M-4, NRHS, N-3*M ) )

and this seems to be the only block that was missing throughout 3.0.0 -
3.1.1. I didn't check earlier LAPACKs.


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