[dylan-lang/opendylan] 0b529c: [deuce] Fix out-of-bounds dline access.

  Branch: refs/heads/deuce-dline-fix
  Home:   https://github.com/dylan-lang/opendylan
  Commit: 0b529c31fd15a91e2717d6c86ae10b44b30a95f0
      https://github.com/dylan-lang/opendylan/commit/0b529c31fd15a91e2717d6c86ae10b44b30a95f0
  Author: Bruce Mitchener <[email protected]>
  Date:   2014-12-28 (Sun, 28 Dec 2014)

  Changed paths:
    M sources/deuce/display.dylan

  Log Message:
  -----------
  [deuce] Fix out-of-bounds dline access.

This could get into a situation where, for example, max-y would be
99, line-y would be continually iterating and increasing and line-height
would be 1, since this was happening in terminal mode.

This is clearly an error in the code as this would happen when resizing:

  let new-size :: <integer>
    = min(max-y, floor(max(ceiling/(max-y, 10), n-slots * 1.5)));
  let new-lines :: <simple-object-vector>
    = make(<simple-object-vector>, size: new-size);

and then after new-lines is moved to be lines:

  dline := lines[n-lines];

So, n-lines needs to be less than max-y and not potentially equal
to it. When line-height is 1, n-lines and line-y are growing at
the same rate and it is more clear that line-y must also remain
less than (and not less than or equal to) max-y.

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