Bug 855 - xterm displays DEL but it should instead ignore it
Summary: xterm displays DEL but it should instead ignore it
Alias: None
Product: xorg
Classification: Unclassified
Component: App/xterm (show other bugs)
Version: unspecified
Hardware: x86 (IA32) Linux (All)
: high normal
Assignee: Xorg Project Team
QA Contact:
URL: http://cvsweb.xfree86.org/cvsweb/xc/p...
Depends on:
Blocks: 351
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Reported: 2004-07-11 11:11 UTC by D. Hugh Redelmeier
Modified: 2004-08-12 12:58 UTC (History)
3 users (show)

See Also:
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Description D. Hugh Redelmeier 2004-07-11 11:11:24 UTC
DEL is a control character that should be (essentially) ignored when written to
a screen.

This was the case for xterm until 2002 Dec 8 when T. Dickey changed the XFree86
version.  This was a mistake, as evidenced by the fact that he has changed it
back (at my prompting) recently (since the fork).

The correct fix is to change the initialization of VTPrsTbl.c's ansi_table[0x7f]
from CASE_PRINT to CASE_IGNORE.  All the other tables defined in this file seem
to have CASE_IGNORE for DEL.

This change was independently derived by me.
Comment 1 D. Hugh Redelmeier 2004-07-11 11:15:03 UTC
test case:
In a bash shell, running in the xterm to be tested, run
  echo -e 'X\177Y'

This should display XY without any glyph or space between them.
Comment 2 Alexandru Fomin 2004-08-02 03:26:24 UTC
It is fixed upstream I think, in xterm patch #188:

Patch #188 - 2004/5/12 - XFree86

    * correct table entry for DEL in the ground state, which marked it as a
printable character from patch #171 (report by D Hugh Redelmeier).

(quote from Thomas E. Dickey site: http://dickey.his.com/xterm/xterm.log.html)

Maybe would be a good ideea to update to latest xterm version (Patch #194 -
2004/7/27) for the upcoming release ..

Comment 3 Alexandru Fomin 2004-08-09 00:33:43 UTC
I'm marking this bug as blocking the next release, hopeing someone will look
into it before the code freeze ...

I know there are more important problems than this one, but I didn't knew other
way to attract attention to it .. If you disagrea please undo my changes ..

The last version of xterm (#195) can be get from Thomas E. Dickey website:
Comment 4 Keith Packard 2004-08-11 22:40:07 UTC
Thomas suggests we go with Xterm version 195 for our release.  Can anyone manage
to get this integrated?
Comment 5 Kristian Høgsberg 2004-08-12 05:01:40 UTC
I'll look into this.
Comment 6 Kristian Høgsberg 2004-08-12 09:44:24 UTC
So, a quick look at the xterm-195 gives 17000 lines of diff between the in-tree
xterm and xterm-195.  5000 or so is in configure, but the rest is actual code
changes.  Do we want to merge this at this point?
Comment 7 Kevin E. Martin 2004-08-12 18:27:48 UTC
Keith Packard said that he talked with Thomas E. Dickey recently and would ask
him if we could/should import his upstream work.  Keith, have you had a chance
to talk with him again?
Comment 8 Keith Packard 2004-08-12 18:54:07 UTC
Given that Thomas is the defacto xterm maintainer at this point, I suggest we
just  go with his current version (#195) which he indicated would suffice for
our release.  I believe most distributions package that separately in any case,
making our inclusion somewhat redundant in any case.
Comment 9 Kristian Høgsberg 2004-08-13 05:58:52 UTC
I just merged in the 195 xterm release.  Yes, this is probably redundant, but
hopefully this will be the last release were we have to do this.

Closing bug, the new xterm passes the testcase in comment #2.

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