XPost: linux.debian.maint.x
From: [email protected]

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Package: xterm
Version: 4.3.0.dfsg.1-6
Severity: normal

The pstree command outputs a process tree, and on a capable terminal
such as xterm it will use some kind of escape sequences to display line
drawing characters(?). It seems that this sometimes confuses xterm
leading to display glitches. Let me try to paste in what I'm seeing:

tqxdmqwqXFree86-debug
x mqxdmqqq.xsessionqwqionqwqfirefo+
x x tqxchatqqqxchat+
x x tqxmmsqqqxmms
x x tqxtermqqqzsh
x x tqxtermqqqzsh
x x tq3*[xtermqqqzs+
x x tqxtermqqqzsh
x x tqxtermqqqzsh
x x tqxtermqqqzsh
x x mqxtermqqqzsh
x tqprocmeter3
x tqssh-agent

Well, it lost the line drawing characters, but you can see some of the x's don't line up. Here's how it is intended to look, from pstree ran with TERM=dumb:

|-xdm-+-XFree86-debug
| `-xdm---.xsession-+-ion-+-firefox-bin---firefox-bin---3*[firefox-bi+
| | |-xchat---xchat---xchat
| | |-xmms---xmms---2*[xmms]
| | |-xterm---zsh---tail---tail
| | |-xterm---zsh---w3m
| | |-xterm---zsh---mutt---editmail---vim
| | |-4*[xterm---zsh]
| | |-xterm---zsh---ssh
| | `-xterm---zsh---pstree
| |-procmeter3

So the indentation is broken with the line drawing characters. At first I assumed this was a pstree bug, but then I straced it:

write(1, " \33(0\17tq\33(Bxdm\33(0\17qwq\33(BXFree"..., 41 tqxdmqwqXFree86-debug
) = 41
write(1, " \33(0\17x\33(B \33(0\17mq\33(Bxdm\33("..., 80 x mqxdmqqq.xsessionqwqionqwqfirefo+
) = 80
write(1, " \33(0\17x\33(B "..., 80 x x tqxchatqqqxchat+
) = 80
write(1, " \33(0\17x\33(B "..., 80 x x tqxmmsqqqxmms
80
write(1, " \33(0\17x\33(B "..., 80 x x tqxtermqqqzsh
80
write(1, " \33(0\17x\33(B "..., 80 x x tqxtermqqqzsh
80
write(1, " \33(0\17x\33(B "..., 80 x x tqxtermqqqzsh
80
write(1, " \33(0\17x\33(B "..., 80 x x tq3*[xtermqqqzs+
) = 80

The strace shows that pstree is properly indenting the lines that do not
diplay indented when it's not straced. Also, notice that after each write() output by strace, we see the actual result of the write, and in each case
xterm managed this time to display the leading indentation properly.

I sshed around to a few other systems, and pstree on those has the
occasional missing indentation too. These systems were running various
versions of pstree. I also tried running it in gnome-terminal, and in
uxterm, and in both cases it displayed ok. I cleared all X resource
setting (xrdb </dev/null; xterm) and can still reproduce the problem; I
also tried running pstree in an xterm (4.3.0.dfsg.1-4) on another computer,
and still saw the problem.

I've managed to capture some pstree output to a file that seems to
reproduce the problem when I cat it in an xterm, even an xterm on
another machine. I've attached that file. When this file is catted,
the result is not identical to the pstree indentation problem I
described above; only one or two lines are displated without
indentation. I hope it's enough to help reproduce the bug.

--
see shy jo

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XPost: linux.debian.maint.x
From: [email protected]

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Thomas Dickey wrote:

On Fri, Aug 13, 2004 at 09:00:13PM +0200, Joey Hess wrote:

Package: xterm
Version: 4.3.0.dfsg.1-6
Severity: normal

that's xterm 191?

e.g., output from
xterm -v

It's 190.

The pstree command outputs a process tree, and on a capable terminal
such as xterm it will use some kind of escape sequences to display line drawing characters(?). It seems that this sometimes confuses xterm
leading to display glitches. Let me try to paste in what I'm seeing:

"sometimes"(?)
- I don't see this behavior when I'm looking for it.
(I saw the previous posting wrt this problem).

I've very confused by the way I see one thing if I run pstree straight,
and another thing if I redirect its output to a file and cat it. Also,
which lines lack indentation seem to vary by what's in my process tree;
for example right now, only one line of my pstree output is
mis-indented, while there were many when I sent the bug.

much of the posting is relatively simple. However -

So the indentation is broken with the line drawing characters. At first I assumed this was a pstree bug, but then I straced it:

write(1, " \33(0\17tq\33(Bxdm\33(0\17qwq\33(BXFree"..., 41 tqxdmqwqXFree86-debug) = 41
write(1, " \33(0\17x\33(B \33(0\17mq\33(Bxdm\33("..., 80 x mqxdmqqq.xsessionqwqionqwqfirefo+) = 80

^^^^^^^^^^^^^^
This caught my eye though. It doesn't correspond to one of the terminal descriptions in ncurses. Checking the source (psmisc), I see that it's
using hardcoded escape sequences in combination with some termcap features. It also has some hardcoded behavior which would make it produce garbage
for ISO-8859-1 text, since it assumes that it must be UTF-8. (I'm
looking at the out_char function in pstree.c). That makes it look like
a problem in psmisc rather than xterm.

It's surely evil code, see bug #265553.

The strace shows that pstree is properly indenting the lines that do not

I'm not certain about "properly" unless I take the whole thing apart.
I'll look at the typescript (though it seemed mangled by the newsreader).

By "properly" I meant only that each line is indented with a seemingly appropriate number of spaces, even though xterm does not always display the leading spaces.

A typescript is a good idea. I've attached one taken with script. When
I did this, and when I play this typescript back with cat, the only line
that is mis-indented is the "xmms" one.

(Note that I use hard-coded escape sequences in my shell's prompt; those
arn't the fault of pstree, but they seem unrelated to this bug.)

diplay indented when it's not straced. Also, notice that after each write() output by strace, we see the actual result of the write, and in each case xterm managed this time to display the leading indentation properly.

I sshed around to a few other systems, and pstree on those has the occasional missing indentation too. These systems were running various versions of pstree. I also tried running it in gnome-terminal, and in uxterm, and in both cases it displayed ok. I cleared all X resource

But when you're running in xterm, what locale?

I don't see the $TERM and locale variables which are in use - those
are relevant.

joey@dragon:~>locale
LANG=en_US
LC_CTYPE="en_US"
LC_NUMERIC="en_US"
LC_TIME=C
LC_COLLATE=C
LC_MONETARY="en_US"
LC_MESSAGES="en_US"
LC_PAPER="en_US"
LC_NAME="en_US"
LC_ADDRESS="en_US"
LC_TELEPHONE="en_US"
LC_MEASUREMENT="en_US"
LC_IDENTIFICATION="en_US"
LC_ALL=

joey@dragon:~>echo $TERM
xterm

I'm using the stock debian xterm terminfo file BTW, though I suspect
pstree does not even use it.

--
see shy jo

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