anchor.diff:        double precision q(1-mbc:mx+mbc,1-mbc:my+mbc,meqn)
   
         integer i,j,k,m,idata,jdata
  -      double precision ibar(0:3),jbar(0:3)
  +      double precision ihat(0:3),jhat(0:3)
         integer idir, i1, j1, i2, j2, ibc, jbc
         logical use_b
   
  -C       data ibar /0.5, 0.5, mx+0.5, mx+0.5/
  -C       data jbar /0.5, my+0.5, my+0.5, 0.5/
  -
  -      ibar(0) = 0.5
  -      ibar(1) = 0.5
  -      ibar(2) = mx+0.5
  -      ibar(3) = mx+0.5
  -
  -      jbar(0) = 0.5
  -      jbar(1) = my+0.5
  -      jbar(2) = my+0.5
  -      jbar(3) = 0.5
  +c     # Lower left corner
  +      ihat(0) = 0.5
  +      jhat(0) = 0.5
  +
  +c     # Lower right corner
  +      ihat(1) = mx+0.5
  +      jhat(1) = 0.5
  +
  +c     # Upper left corner
  +      ihat(2) = 0.5
  +      jhat(2) = my+0.5
  +
  +c     # Upper right corner
  +      ihat(3) = mx+0.5
  +      jhat(3) = my+0.5
   
         do m = 1,meqn
             do k = 0,3
  
positive.code:       return
        end
  
  
        subroutine clawpack46_fix_corners(mx,my,mbc,meqn,q,sweep_dir,
       &             block_corner_count)
        implicit none
  
negative.code:                q1d(j,m) = qold(i,j,m)
              enddo
           enddo
  c
           if (mcapa .gt. 0)  then
             do  j = 1-mbc, my+mbc
  