bm_delete()... what's wrong with it?

[OldRover]

Supposedly, there is an error with the bm_delete() library function. I don't know enough about the underlying code to figure out where the issue is, and I have not used it yet so I don't know its symptoms.

Code Select Expand

lib2_bm_delete:
__stw <_ax
  jsr lib2_bm_open
  bcs .out
  stw $8006,<_bx ; ptr to end
  stw <_si,<_di ; setup currptr as dest
  stw <_dx,<_si ; setup nextptr as src
  subw <_dx,<_bx ; #bytes = end-next + 2
  addw #2,<_bx
  subw <_cx,$8006 ; adjust ptr to end
  lda <_bh
  ldx <_bl
  jsr _memcpy.3
  jsr lib2_bm_disable
  stz _bm_error
  clx
  cla
  clc
.out:   rts
EDIT: an old thread on the ME forum sheds some light on the issue:
http://forums.magicengine.com/en/viewtopic.php?t=1744

[OldRover]

Code Select Expand

    lda   _Nulltard
    ldx   _bullets
    inx
    txa
    sbc   _Nulltard
    jsr   _cheap_funeral
    nop
    rts

[OldRover]

Yeah, I got the joke. BM, bowel movement, flush it down the toilet.