anchor.diff:         ! count data lines
          nseqs = 0
          do
  -          read(udata,'(a)',iostat=err) line
  +          read(udata, '(a)', iostat=err) line
             ! exit at end of file or empty line
             if( err < 0 .or. len_trim(line) == 0) exit
             nseqs = nseqs + 1
  
positive.code: 
  contains
  
    subroutine data_read(iproc,udata,data_type,uwgt,wid,nvars,nclasses,&
                         nseqs,neff,seqs,error_code,error_string)
      use fasta, only: fasta_read
      integer,              intent(in)    :: iproc
      integer,              intent(in)    :: udata
  
negative.code: 
      end if
  
      if (wid > 0.0_kflt) then 
  
         call data_reweight(seqs, wid, iproc)
  
      end if
  
  