Bug 260598

Summary:	lost a line in backlog
Product:	[Applications] konversation	Reporter:	Modestas Vainius <modax>
Component:	ircview	Assignee:	argonel <argonel>
Status:	RESOLVED FIXED
Severity:	major	CC:	hein, konversation-devel
Priority:	NOR
Version:	Git
Target Milestone:	---
Platform:	Debian unstable
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:

Description Modestas Vainius 2010-12-18 01:16:55 UTC

Version:           Git (using KDE 4.4.5) 
OS:                Linux

Just compare this excerpt from the backlog in ircview (#konversation):

[2010-12-18 01:48:49] <MoDaX> buscher: actually I'm suffering from that one. using intel
[2010-12-18 01:49:56] <MoDaX> that was about bug 253560
[2010-12-18 01:49:58] <bugbot> KDE bug 253560 in konversation (general) "Konversation is very (++) slow" [Normal,Resolved: worksforme] http://bugs.kde.org/253560
[2010-12-18 01:51:00] <MoDaX> that's an example of what happens when I leave scrollbar not at the bottom :)
[2010-12-18 01:54:21] <PovAddict> MoDaX: we could add a Clippy clone that tells you "it looks like you're writing a message but you didn't read everything yet"
[2010-12-18 01:55:59] <MoDaX> PovAddict: was there a solution? scrollback was eaten as soon as scrolled down
[2010-12-18 01:56:30] <PovAddict> huh?
[2010-12-18 01:58:05] <MoDaX> nevermind


with respective log from the file:

[Saturday 18 December 2010] [01:48:49] <MoDaX>	buscher: actually I'm suffering from that one. using intel
[Saturday 18 December 2010] [01:49:46] <MoDaX>	oops, 3 days too late
[Saturday 18 December 2010] [01:49:56] <MoDaX>	that was about bug 253560
[Saturday 18 December 2010] [01:49:58] <bugbot>	KDE bug 253560 in konversation (general) "Konversation is very (++) slow" [Normal,Resolved: worksforme] http://bugs.kde.org/253560
[Saturday 18 December 2010] [01:51:00] <MoDaX>	that's an example of what happens when I leave scrollbar not at the bottom :)
[Saturday 18 December 2010] [01:54:21] <PovAddict>	MoDaX: we could add a Clippy clone that tells you "it looks like you're writing a message but you didn't read everything yet"
[Saturday 18 December 2010] [01:55:59] <MoDaX>	PovAddict: was there a solution? scrollback was eaten as soon as scrolled down
[Saturday 18 December 2010] [01:56:30] <PovAddict>	huh?
[Saturday 18 December 2010] [01:58:05] <MoDaX>	nevermind


As you see, the line "[Saturday 18 December 2010] [01:49:46] <MoDaX>	oops, 3 days too late" is not present in the ircview backlog. However, at some point I actually remember it being there. But later I scrolled the chat window back and forth. I guess it was the time it had vanished.

In my opinion, it's a data loss bug so I'm marking it as such. Feel free to downgrade severity if you disagree though.

Reproducible: Didn't try

Comment 1 Eike Hein 2010-12-18 15:33:48 UTC

Was this toward the very upper end of the backlog? Konversation pauses its scrollback culling (culling to conform to the user-configured limit) while a view is scrolled up, and then resumes culling when the view is scrolled back down. Obviously it should always cull the oldest lines, but maybe it somehow grabbed the wrong one.

Alternatively it may be somehow related to moving the automatic remember line; do you have it enabled?

Comment 2 Modestas Vainius 2010-12-18 17:21:25 UTC

No, this backlog was at the very bottom. The line disappeared (or rather I noticed this) ~ 2 minutes after I posted it.

Yes, I have automatic remember line enabled.

Comment 3 argonel 2011-09-30 10:49:01 UTC

Git commit cbe876c954b5deaf1a6729b7123d6880df4513ee by eli mackenzie.
Committed on 30/09/2011 at 12:41.
Pushed by argonel into branch 'master'.

Changed method of remember/marker line tracking.

Qt 4.7.4 introduces a change to the handling of
QTextBlock::userState that makes it unusable for the purposes of
tracking which block represents a marker or remember line. Previous
versions of Qt also changed or otherwise corrupted the userState
value causing the loss of synchronization with the data held in the
IRCView itself. Blocks are now tracked via the userData field, which
was unmolested in the change made to QTextDocument.

Warning: this commit introduces a large volume of debugging output.

For more information about the Qt change, see QTBUG-20916.

BUG: 210106
CCBUG: 260598

M  +1    -1    src/commit.h
M  +17   -0    src/irc/outputfilter.cpp
M  +1    -0    src/irc/outputfilter.h
M  +278  -95   src/viewer/ircview.cpp
M  +16   -9    src/viewer/ircview.h

http://commits.kde.org/konversation/cbe876c954b5deaf1a6729b7123d6880df4513ee

Comment 4 Eike Hein 2012-04-09 00:44:50 UTC

Modax, can you still reproduce this?

Comment 5 Modestas Vainius 2012-04-09 07:39:44 UTC

I have not seen it for a while, but TBH, I was not paying much attention. Let's close it.