#1006 W98: wish hangs after panic

[miguel sofer]

(see also tcl-bug #406709, already closed)

Apparently wish hangs after a panic: "The error causes
Wish to hang, and CPU and memory usage goes up to near
maximum. The wish and console windows remain visible
but do not redraw if you cover and uncover them with
another app (you are left with white window-shaped
objects). The only solution is to reboot the computer.
"

The problem has been reported on Win98SE, apparently
happens also in Win98SP2.

The scriptlet
while 1 {puts [break]}
should exercise the bug up to tcl8.4a2 (but *not* in
current sources)- it causes a panic. tclsh apparently
exits cleanly, but wish hangs as reported.

The first report included the script
proc createByteCodeBug {} {
set path [frame .frame];

entry $path.command;
text $path.text;

pack $path.command -side bottom -fill x -expand
1;
pack $path.text -side top -fill both -expand 1;

$path.command configure -state disabled;
$path.text configure -state normal;
focus $path.text;
foreach {dir equiv} [list Up k Down j Left h
Right l] {
bind $path.text <Key-$dir> {}
bind $path.text <Key-$equiv> [concat [bind
Text <Key-$dir>]; break];
}
}

createByteCodeBug

[miguel sofer]

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The bug has been reported on W98SE and W98SP2; it apparently
does not happen in W95 or W2000.

[Jeffrey Hobbs]

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I cannot reproduce this problem with 8.3 cvs head on Win98.
Was there something more here, or is it likely fixed by the
ref'd bug report, which had a patch applied?

[miguel sofer]

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The provided script will not fire the bug anymore, as Tcl
will no longer panic - *that* bug was indeed fixed. My
understanding is that there were two bugs (1. the script
causes panic() to be called; 2. panic() causes wish to
hang), and that the first one is fixed.
The way to test for the presence of the bug is to cause a
call to panic() - hopefully only possible from C, anything
else would be a new bug as scripts shouldn't panic.
This may or may not be related to other problems reported in
pyTk at app end - a possible common description being
"wish/W98 has problems shutting down abruptly".

[Don Porter]

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lost bug needs a home

[Donal K. Fellows]

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I'm not in a position to help on this except for testing
builds occasionally (my W98 machine is on a very slow link.)