Created attachment 180340 [details]
Zipped folder with Spreadsheet, screen shot of horizontal lines and screen shot of Open GL viewer

I do not have any white lines, neither with Skia enabled nor with Skia disabled. I have tested it with Version: 7.3.2.2 (x64) / LibreOffice Community
Build ID: 49f2b1bff42cfccbd8f788c8dc32c1c309559be0
CPU threads: 8; OS: Windows 10.0 Build 19043; UI render: Skia/Raster; VCL: win
Locale: de-DE (en_US); UI: en-US
Calc: CL

Please post the version info from Help > About.

Version: 7.2.6.2 (x64) / LibreOffice Community
Build ID: b0ec3a565991f7569a5a7f5d24fed7f52653d754
CPU threads: 2; OS: Windows 10.0 Build 19044; UI render: default; VCL: win
Locale: en-CA (en_CA); UI: en-US
Calc: threaded

I have a couple of other observations.

1. I just noticed that when a new image is loaded, it is clean, that is no white lines. When I do Alt-J, which aligns the view so that the AM weather block is positioned nicely and sets the active cell to be the first data cell for the AM weather, the lines appear on the image. Because the weather block is aligned so that the top corner of the AM weather data is at the top left corner of the spreadsheet, you can't see the white lines unless you do a Ctrl-Home.


2. You will notice, just from the screen capture I sent in the Zip file, that the horizontal white lines correspond to the tops and bottoms of the buttons along the left side of the spreadsheet.

3. On occasion, the first time I do a CopyDown, Alt-], I see a quick flash of the buttons displayed, even though they are out of sight of the current view. This makes we wonder if the way the buttons are displayed has something to do with the white lines and the occasional flash of buttons.

I just went to the next day's image. After the date was set, I did a Ctrl-Home. No white lines. I moved around with arrow keys, no macros, so Cell C4 was top left in the Calc window. I entered a number in D5, did Ctrl-Home and the lines were there.

While I was looking at the screen, Calc did an Auto-Save. Initially there were no white lines associated with the bottom two buttons, but they appeared after the Auto-Same.

I'm not sure if this helps.

One last observation. These images are very large, about 13777483. We have about 27 different spreadsheets active. They are needed to accommodate the many different logbook formats for the various ships and years.

When I saved this spreadsheet and re-opened it, I got just one white line. I suspect I might see none or more if I did this repeatedly. However, just scrolling so the buttons on the side are completely out of view and then doing a Ctrl-Home, I see all the white lines.

I did the same thing with a different spreadsheet that has a much smaller image: 4222314. No white lines appeared mo matter how I was moving around, or if I was entering data.

So, it seems to have a problem with the very large images. Perhaps it is just my generic video card, i don't know.

(In reply to Michael from comment #4)
> I have a couple of other observations.
> 
> 1. I just noticed that when a new image is loaded, it is clean, that is no
> white lines. When I do Alt-J, which aligns the view so that the AM weather
> block is positioned nicely and sets the active cell to be the first data
> cell for the AM weather, the lines appear on the image. Because the weather
> block is aligned so that the top corner of the AM weather data is at the top
> left corner of the spreadsheet, you can't see the white lines unless you do
> a Ctrl-Home.

I tried with the last commit in the Windows 7.2 bibisect repository and the latest unstable, but I don't see the issue.

Do you still see this with 7.4?

Set to NEEDINFO.
Change back to UNCONFIRMED, if the problem persists. Change to RESOLVED WORKSFORME, if the problem went away.

Version: 7.6.0.0.alpha0+ (X86_64) / LibreOffice Community
Build ID: c68d06dfa1498f862923eaddf3e5d247650a53d5
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

Yes, the white lines are still there.

Version: 7.4.2.3 (x64) / LibreOffice Community
Build ID: 382eef1f22670f7f4118c8c2dd222ec7ad009daf
CPU threads: 2; OS: Windows 10.0 Build 19044; UI render: default; VCL: win
Locale: en-CA (en_CA); UI: en-US
Calc: threaded

Have downloaded the attached zip. 
Opened the attached file with hardware acceleration turned on, anti-aliasing turned off.
When scrolling down with mouse there appears one white line.

Tested with 
Version: 7.5.0.1 (X86_64) / LibreOffice Community
Build ID: 77cd3d7ad4445740a0c6cf977992dafd8ebad8df
CPU threads: 6; OS: Linux 5.3; UI render: default; VCL: kf5 (cairo+xcb)
Locale: de-DE (de_DE.UTF-8); UI: de-DE
Calc: threaded

also with 
LO 7.4.4.2 on OpenSUSE 15.3 64bit rpm Linux.

Tried a little bit more: The white line depends on the buttons at the left.
When setting button Log | Events from position y = 9.7 cm to 9.6 cm the white line won't appear again.

Created attachment 184616 [details]
Image showing several white lines.

Sorry, I wrote a comment and I thought attaching the image would go with the comment.

The number of white lines varies, sometimes you get one, and sometimes you get several. The white lines always appear lined up with the top and/or bottom of the buttons. Each time I process the data for a new day, you get some different number of white lines. The only consistency is that any lines that appear line up with the buttons.

I haven't seen the white lines for quite some time, but I can't remember when they stopped appearing. With this project we're working on, I load several hundred images per week. Yesterday, I processed 56, so I would have noticed if any were there. Right now, I'm running:

Version: 24.8.5.2 (X86_64) / LibreOffice Community
Build ID: fddf2685c70b461e7832239a0162a77216259f22
CPU threads: 4; OS: Windows 11 X86_64 (10.0 build 26100); UI render: Skia/Raster; VCL: win
Locale: en-CA (en_CA); UI: en-US
Calc: CL threaded

I am reluctant to install the latest version of LO. When I was running that version and turned on image enhancement, LO became VERY slow to the point of being unusable. I had to uninstall it, and re-install the version I'm using now. I filed a bug report about that, which is here:

https://bugs.documentfoundation.org/show_bug.cgi?id=165595

As you can see, people are working on that.

If you really like, I could install 25.2 and doublecheck for the white lines but I am confident that the white lines were not there. 

Please let me know if you would like me to try it for you.

That's great to hear, let's close and celebrate.

Sorry, I spoke too soon. After I sent my reply, I realized I had different settings when I originally reported the bug than I do now.

With:

 Hardware acceleration on
 Anti-aliasing off
 Skia off

I get the white lines.

With:

 Hardware acceleration on
 Anti-aliasing on
 Skia off

I get no white lines.

And with:

 Hardware acceleration on
 Anti-aliasing on
 Skia on

I get no white lines.

I installed 25.2.2

Version: 25.2.2.2 (X86_64) / LibreOffice Community
Build ID: 7370d4be9e3cf6031a51beef54ff3bda878e3fac
CPU threads: 4; OS: Windows 11 X86_64 (10.0 build 26100); UI render: default; VCL: win
Locale: en-CA (en_CA); UI: en-US
Calc: CL threaded

With the original settings: Hardware accel on, anti-aliasing and Skia off, the white lines appear when an image is loaded. When I turn on Anti-aliasing, there are no white lines when an image is loaded. It seems that the Anti-aliasing setting is the key as to whether there are white lines or not. The Hardware acceleration setting has no effect on the white lines, nor does the Skia rendering.

Now, I'll uninstall 25.2.2 and go back to 24.5.8