Re: Bug busting session next week.

[Carey Evans <c.evans@xxxxxxxxxxxx>]

Mike Madore <mmadore@mail.turbolinux.com> writes:

> I am going to have access to an AS/400 for the week of April 10th.  I
> would like to get a list of outstanding bugs so that I can make maximum
> use of my time while I am there.

Here's some bugs I'm aware of at the moment.  Let me know if you want
tracefiles for any of them.

* BUGS
======

** Cursor positioning.

The cursor doesn't appear in the correct place in at least two places.
Instead it appears at the start of the first field.  In particular,
this happens with DFU.  On a slow link, I see the screen appear with
the cursor in the correct place, then X SYSTEM is displayed again, the
function key labels are drawn, and the cursor pops up to the first
field.

It also reappears in the first field if a break message is displayed.
It should come back exactly where it was before.


** Assertion 0 failed at session.c, line 339.

This appears when the X SYSTEM display isn't showing, when a real 5250
or Client Access does show it.  I can duplicate this in two places:
edit a record in DFU and press Enter several times quickly; or exit
from interactive SQL and press Enter very quickly twice.

Both of these seem easier to get on a slow link.


** Field Exit in Field Exit Required position.

In a field exit required field, pressing Field Exit with the field
filled and the cursor in the Field Exit Required state erases the last
character.  The last character should be left alone, unless something
has to be done for signed fields.

DFU fields seem to be FER by default, so this is a good place to test
this.


* BUGLETS
=========

** Non DEC-alike terminals.

On terminals such as the IBM 3151 where some of the keypress escape
sequences are the same as our built-in keys, or longer, then those
keys will never get detected.  For example, F13 to F24 on the IBM 3151
begin with "^[!", but this is F13 in tn5250.

curses uses its delay to guess whether "^[ ! h ^M" is "Meta-! h Enter"
or F20.


** End of field in an empty field.

Pressing End on the QCMD display, when nothing's been entered, moves
the cursor two the second position in the field.


** Screen redraws on 80 -> 132 column switch.

Sometimes, when the screen is switched to 132 columns, it isn't
redrawn until the next keyboard activity, including Esc on its own,
which doesn't generate any screen output.


** recv with buffer length of 1.

telnetstr.c line 224 always reads just a single character.  Each
recv() results in a system call, and even on Linux this is quite
expensive, since it requires a context switch into and out of kernel
mode, and the TCP/IP drivers probably aren't designed for this access
pattern either.  tn5250 would run faster if some kind of buffering was
used.

In addition, SNA itself is more of a datagram protocol, which the
tn5250 datastream emulates with GA.  It might be easier to deal with
this if tn5250 gets ported to SNA, if buffering is implemented now.



* WIBNI¹
========

¹ Wouldn't It Be Nice If....

Some terminals only have 24 rows.  Maybe X SYSTEM, etc., should
obscure the line above in this case, so that the user can still get
some idea of what's going on.

On terminals that don't support blinking text, such as xterm, tn5250
could do it itself by repainting the fields every half a second.  This
would have to be easily disabled if it was the default.

IBM's Client Access for DOS does the underscore-for-underline trick,
but it doesn't draw the underscore for spaces that have been typed
in. only for positions containing nulls as far as I can tell.  I'd
gotten used to this.

tn5250 seems to repaint the whole screen more often than needed.  It
would be nice if only the parts that were changed in the datastream
received from the AS/400 were redrawn, with a key like ^L or ^R to
redraw the whole screen if this goes wrong.

The latest versions of IBM Client Access Express will work out which
session name to use if the first one isn't available.  My PC is
configured for a session name of "+&COMP%=", which tries "EVANSCS1",
"EVANSCS2", etc. until one of them works.  It would be nice to be able
to do this in tn5250 too.

System Request is supposed to display a line for the request number to
be typed on, instead of going straight to the menu.  This is
definitely not a priority, but I wanted to mention it.


-- 
         Carey Evans  http://home.clear.net.nz/pages/c.evans/

"Validate me!  Give me eternal digital life!  Quote me in your .sigs!"
                                                             - djc in asr
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