[petsc-users] Bug report LMVM matrix class

[Stephan Köhler]

Dear PETSc/Tao team,

it seems to be that there is a bug in the LMVM matrix class:

In the function MatCreateVecs_LMVM, see, e.g., 
https://petsc.org/release/src/ksp/ksp/utils/lmvm/lmvmimpl.c.html at line 
214.
it is not checked if the vectors  *L, or *R are NULL.  This is, in 
particular, a problem if this matrix class is combined with the Schur 
complement matrix class, since MatMult_SchurComplement
calls this function with NULL as *R, see, e.g. 
https://petsc.org/release/src/ksp/ksp/utils/schurm/schurm.c.html at line 66.

I attach a minimal example.  You need to modify the paths to the PETSc 
installation in the makefile.

Best regards
Stephan Köhler

-- 
Stephan Köhler
TU Bergakademie Freiberg
Institut für numerische Mathematik und Optimierung

Akademiestraße 6
09599 Freiberg
Gebäudeteil Mittelbau, Zimmer 2.07

Telefon: +49 (0)3731 39-3173 (Büro)

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