Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!uunet!mcsun!hp4nl!eutrc3!tuewsd!wsinpp
From: wsinpp@lso.win.tue.nl (Peter Peters)
Newsgroups: comp.lang.pascal
Subject: TP BUG
Keywords: TP, WINDOWS, BUG
Message-ID: <819@tuewsd.lso.win.tue.nl>
Date: 22 Jan 90 12:52:03 GMT
Organization: Eindhoven University of Technology, The Netherlands
Lines: 64


Dear fellow TP users,

I had a close encounter of the bug kind a few days ago and I
wonder if this TP bug is known, and if so if a solution is
available.

The problem is as follows :

Any window defined using the Window procedure from the Crt Unit
with a height of 1 line (in textmode) will scroll erroneously.
A program demonstrating what I mean follows this text.
This bug was present in TP 3.x. If I remember correctly is was
fixed in TP 4.x. Since I'm using TP 5.x (currently 5.5) it seems
to be back again. I'm quite sure it's not a "feature", but a bug.
Any advice/comment (that makes sense) is gladly accepted.

--Here's the program -- Here's the program -- Here's the program --

Program BugAgain;
(*
 * Demonstrate a bug which was present in TP 3.x (I patched it out
 * myself), was corrected in TP 4.x and seems to be present again
 * in TP 5.x
 *)

Uses
  Crt;

Const
  Xloc   = 10;
  Yloc   = 10;
  Width  = 30;
  Height = 1;   (* This is the troublesome height !!! *)

Var
  i : Word;

Begin
  Window(1,1,80,25);       (* Whole screen *)
  ClrScr;                  (* Clear *)
  For i := 1 To 80*24 Do   (* Fill it up with dashes to *)
    Write('-');            (* clearly show what happens *)
  Window(Xloc,Yloc,Xloc-1+Width,Yloc-1+Height);
  ClrScr;
  (* Watch what happens when this window scrolls if it's 1 line high !!! *)
  For i := 1 To Width+10 Do Begin
    Write('a');
    Delay(100);
  End;
End.

-- Ttttthat's all folks ----------------


| Peter Peters                              | UUCP : wsinpp@lso.win.tue.nl  |
| Eindhoven University of Technology (TUE)  | SURF : heithe5::wsdcpp        |
| Dept. of Mathematics and Computer Science | VHF  : PA0PPE                 |
| Disclaimer : I said WHAT ???              | TUE  : HG 8.86 tst. 4283      |
-- 
| Peter Peters                              | UUCP : wsinpp@lso.win.tue.nl  |
| Eindhoven University of Technology (TUE)  | SURF : heithe5::wsdcpp        |
| Dept. of Mathematics and Computer Science | VHF  : PA0PPE                 |
| Disclaimer : I said WHAT ???              | TUE  : HG 8.86 tst. 4283      |