In restrict_between_reference_positions subroutine, now update $self->reference_slice_start and $self->reference_slice_start only if $self->reference_slice is defined
In restrict_between_reference_positions subroutine, now update $self->reference_slice_start and $self->reference_slice_start only if $self->reference_slice is defined

etapanari/ensembl-compara,ckongEbi/ensembl-compara,Ensembl/ensembl-compara,Ensembl/ensembl-compara,danstaines/ensembl-compara,etapanari/ensembl-compara,danstaines/ensembl-compara,Ensembl/ensembl-compara,Ensembl/ensembl-compara,Ensembl/ensembl-compara,ckongEbi/ensembl-compara,dbolser-ebi/ensembl-compara,kumarsaurabh20/ensembl-compara,ckongEbi/ensembl-compara,kumarsaurabh20/ensembl-compara,kumarsaurabh20/ensembl-compara,Ensembl/ensembl-compara,Ensembl/ensembl-compara,danstaines/ensembl-compara,etapanari/ensembl-compara,danstaines/ensembl-compara,danstaines/ensembl-compara,Ensembl/ensembl-compara,kumarsaurabh20/ensembl-compara,dbolser-ebi/ensembl-compara,etapanari/ensembl-compara,dbolser-ebi/ensembl-compara