Bug 361834

Summary:	Incorrect calculation of repaint region when message display pane is close to requiring scroll bars?
Product:	[Applications] kmail2	Reporter:	Kjetil Kilhavn <kjetil>
Component:	UI	Assignee:	kdepim bugs <kdepim-bugs>
Status:	RESOLVED WORKSFORME
Severity:	normal
Priority:	NOR
Version:	5.1.3
Target Milestone:	---
Platform:	openSUSE
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:
Attachments:	Message that caused the erratic behaviour Message displayed as plain text (default in my configuration) Message displayed as HTML without external resources (top of message) Message displayed as HTML without external resources (bottom of message) Message displayed as HTML with external resources Window screenshot of message in separate window (for easier recreation of same window size)

Description Kjetil Kilhavn 2016-04-15 20:01:23 UTC

An email message that in its HTML form contains a background image which is an external resource leads to a display anomaly when loading external resources.
The problem occurs only for specific window sizes, so I suspect it is related to calculation of the region that must be repainted.

I accidentally discovered that if I turn on display of message structure (displayed below message pane) the problem does not occur! So I experimented a little more with the message opened in a separate window and discovered that the problem did not occur then either. However; it turns out that it depends on the window size - so when changed the size of the separate message window to match the message area size in KMail the problem occurred again. It did not occur for a smaller window, nor for a larger window.
I suspect that with a larger screen I would be able to reproduce the problem also with the message structure displayed.

Reproducible: Always

Steps to Reproduce:
If required, change KMail settings to display plain text email by default and display HTML status bar in message window before attempting to reproduce the problem.

1. Load attached message into KMail
2. Switch to HTML version
3. Load external resources

Actual Results:
The right edge of the window (where the scroll bar was before loading external resources) is not repainted correctly. It shows the mail header and parts of the background - from the size distortion it seems there is an initial rendering run, and the scroll bar area shows the result of this rendering.

Expected Results:
The message should have displayed without a strange artefact in the scrollbar area.

I am setting the severity to Normal instead of Minor because I hope there can also be some performance gained from fixing this bug - assuming a fix leads to a 50% reduction in rendering runs (from 2 to 1).

Comment 1 Kjetil Kilhavn 2016-04-15 20:02:38 UTC

Created attachment 98410 [details]
Message that caused the erratic behaviour

Comment 2 Kjetil Kilhavn 2016-04-15 20:03:50 UTC

Created attachment 98411 [details]
Message displayed as plain text (default in my configuration)

Comment 3 Kjetil Kilhavn 2016-04-15 20:04:28 UTC

Created attachment 98412 [details]
Message displayed as HTML without external resources (top of message)

Comment 4 Kjetil Kilhavn 2016-04-15 20:05:05 UTC

Created attachment 98413 [details]
Message displayed as HTML without external resources (bottom of message)

Comment 5 Kjetil Kilhavn 2016-04-15 20:05:49 UTC

Created attachment 98414 [details]
Message displayed as HTML with external resources

Comment 6 Kjetil Kilhavn 2016-04-15 20:06:49 UTC

Created attachment 98415 [details]
Window screenshot of message in separate window (for easier recreation of same window size)

Comment 7 Justin Zobel 2022-10-20 23:54:29 UTC

Thank you for reporting this bug in KDE software. As it has been a while since this issue was reported, can we please ask you to see if you can reproduce the issue with a recent software version?

If you can reproduce the issue, please change the status to "CONFIRMED" when replying. Thank you!

Comment 8 Bug Janitor Service 2022-11-04 05:07:15 UTC

Dear Bug Submitter,

This bug has been in NEEDSINFO status with no change for at least
15 days. Please provide the requested information as soon as
possible and set the bug status as REPORTED. Due to regular bug
tracker maintenance, if the bug is still in NEEDSINFO status with
no change in 30 days the bug will be closed as RESOLVED > WORKSFORME
due to lack of needed information.

For more information about our bug triaging procedures please read the
wiki located here:
https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging

If you have already provided the requested information, please
mark the bug as REPORTED so that the KDE team knows that the bug is
ready to be confirmed.

Thank you for helping us make KDE software even better for everyone!

Comment 9 Kjetil Kilhavn 2022-11-12 21:22:51 UTC

Sorry about the late response. I have tried to recreate the problem, but have not been able to do so - so the problem was probably solved a long time ago. I currently use openSUSE Leap 15.4 and Plasma 5.24.4 with KMail version 5.19.3.

Thank you for your continuous improvement of my favourite software and desktop environment.

Shortly after I reported the bug I started using Ubuntu and used that the next four or so years as Dell was the only computer available in Norway with a Linux-based operating system preinstalled and supported. 
I really enjoyed that laptop (XPS 13 developer edition) - I wish something similar becomes available with KDE, because I believe in voting with my wallet and supporting companies that offer a supported Linux installation. Unfortunately, today we are back to the normal situation in Norway; you can only buy a computer without Windows or MacOS if you settle for FreeDOS.