Bug 141265 - Random characters appear as black boxes at certain zoom levels in windows 10.
Summary: Random characters appear as black boxes at certain zoom levels in windows 10.
Status: RESOLVED WORKSFORME
Alias: None
Product: LibreOffice
Classification: Unclassified
Component: Writer (show other bugs)
Version:
(earliest affected)
6.4.6.2 release
Hardware: x86-64 (AMD64) Windows (All)
: medium normal
Assignee: Not Assigned
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2021-03-26 14:14 UTC by Allan Macdonald
Modified: 2024-02-05 16:47 UTC (History)
2 users (show)

See Also:
Crash report or crash signature:


Attachments
Document and screenshots that exhibited the issue. (240.60 KB, application/x-zip-compressed)
2021-03-26 14:17 UTC, Allan Macdonald
Details
Document and screenshots (1.02 MB, application/x-zip-compressed)
2022-04-28 13:38 UTC, Allan Macdonald
Details

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Description Allan Macdonald 2021-03-26 14:14:56 UTC
Description:
Randomly, a character that appears normal at one zoom level, appears as a black box at another zoom level.  In the attached example, the screen shot shows black rectangles at zooom level 200% and normal characters at other zoom levels.

This happens randomly to some documents and then seems to mysteriously disappear.

Steps to Reproduce:
1. Open the example document - should open at 200%.
2. Zoom out - black boxes disappear
3. Zoom in to 200%, black boxes re-appear
4. Zoom in further, black boxes disappear agaion

Actual Results:
Black boxes appear at certain zoom levels.

Expected Results:
Black boxes should never appear at any zoom level.


Reproducible: Sometimes


User Profile Reset: No


OpenGL enabled: Yes

Additional Info:
I don't have adequate knowledge to determine if this is caused by the Graphics Stack or Writer itself - I am leaning towards the Graphics stack but I would rather let someone else make the determination.

Document and screenshots to follow.
Comment 1 Allan Macdonald 2021-03-26 14:17:11 UTC
Created attachment 170763 [details]
Document and screenshots that exhibited the issue.
Comment 2 Dieter 2021-04-10 10:22:29 UTC
Thank you for reporting the bug. It seems you're using an old version of LibreOffice. Could you please try to reproduce it with the latest version of LibreOffice from https://www.libreoffice.org/download/libreoffice-fresh/ ? I have set the bug's status to 'NEEDINFO'. Please change it back to 'UNCONFIRMED' if the bug is still present in the latest version. Change to RESOLVED WORKSFORME, if the problem went away.
Comment 3 Allan Macdonald 2021-07-06 21:11:37 UTC
The behavour is still happening in the following version:
Version: 7.1.4.2 (x64) / LibreOffice Community
Build ID: a529a4fab45b75fefc5b6226684193eb000654f6
CPU threads: 4; OS: Windows 10.0 Build 19042; UI render: Skia/Raster; VCL: win
Locale: en-CA (en_CA); UI: en-GB
Calc: threaded

Some additional info:

The effect occurs when a document is being worked on for an extended period - say several hours to a couple of days.

The behaviour also seems to be more likely to occur when there is at least one LibreOffice document opened through a samba share, say a spreadsheet document.  The effect though does not necessarily involve the remote document - the effect occurs on the document residing on the local hard drive.
Comment 4 QA Administrators 2021-07-07 04:04:19 UTC Comment hidden (obsolete)
Comment 5 Dieter 2021-07-30 17:01:21 UTC
Could you please try it again without Skia rendering: Tools -> Options -> LibreOffice -> View and then deselect "Use Skia for all rendering"
=> NEEDINFO
Comment 6 QA Administrators 2022-01-28 03:58:21 UTC Comment hidden (obsolete)
Comment 7 Allan Macdonald 2022-01-28 16:57:36 UTC
(In reply to Dieter from comment #5)
> Could you please try it again without Skia rendering: Tools -> Options ->
> LibreOffice -> View and then deselect "Use Skia for all rendering"
> => NEEDINFO

Hi Dieter,

Sorry for the slow response - I missed the original notification of your posting buried in my inbox!

I have changed the option as suggested and will report back later.  It takes some time for the behaviour to appear and I only use my Windows machine at work so it may take a little while for me to get back to this.

Regards,
Allan

p.s.
Could we reset the needinfo timer?
Comment 8 Allan Macdonald 2022-01-28 17:26:26 UTC
Resetting to needinfo now
Comment 9 QA Administrators 2022-01-29 03:55:20 UTC Comment hidden (obsolete)
Comment 10 Allan Macdonald 2022-04-28 13:38:45 UTC
Created attachment 179825 [details]
Document and screenshots

As instructed, I have turned off "Use Skia for all rendering" but the problem persists.  Attached shows a document exhibiting the issue plus a screenshot of the problem and a screenshot of the settings window.
Comment 11 mlbleak 2022-06-24 18:55:33 UTC
I tried to replicate this bug but I did not have any success. I kept my files open for a couple days and tried various zoom levels, but I never was able to observe this reported bug. With your original observations, did this happen with multiple font types and font sizes, or only with the font and size that was set in your attached documents?
Comment 12 Buovjaga 2023-01-19 09:00:31 UTC
Works fine for me

Version: 7.6.0.0.alpha0+ (X86_64) / LibreOffice Community
Build ID: fc441f3886330c4ae2abeb67c0758b935ba23f47
CPU threads: 2; OS: Windows 10.0 Build 22621; UI render: Skia/Raster; VCL: win
Locale: en-US (en_FI); UI: en-US
Calc: threaded
Comment 13 Dieter 2024-02-03 05:21:09 UTC
(In reply to Buovjaga from comment #12)
> Works fine for me
> 

Allan, does the problem still appear in LO actual version 24.2?
=> NEEDINFO
Comment 14 Allan Macdonald 2024-02-05 16:44:57 UTC
Hi,

I got myself a new Win 11 machine in May of 2023.  My old Win 10 box went kaput.

I don't think I've ever seen this issue on my new machine.  However, I did recently notice that LO seemed sluggish so I then turned on Skia for all rendering (not sure why it was off) and things sped up considerably.  I haven't seen any funny artifacts.

Since I don't see the issue anymore, I suppose that you could mark this bug as "worksforme".

Additional info:

Version: 7.6.4.1 (X86_64) / LibreOffice Community
Build ID: e19e193f88cd6c0525a17fb7a176ed8e6a3e2aa1
CPU threads: 20; OS: Windows 10.0 Build 22621; UI render: Skia/Vulkan; VCL: win
Locale: en-CA (en_CA); UI: en-US
Calc: CL threaded

Graphics: Nvidia T400 4GB