Newly added note-anchored line has zero length (sometimes)

[chrishafner]

Issue type

UX/Interaction bug (incorrect behaviour)

Description with steps to reproduce

1. Create a new score with piano.
2. Add notes as seen in the screenshot below.
3. Select notes 1S & 1E, and click Add > Lines > Note-anchored line.
4. Repeat step 3 for notes 2S & 2E, 3S & 3E, and 4S & 4E.

Current behavior (4.5.2): A line appear between 1S & 1E; a very short line appears between 2S & 2E; no (visible) lines appear between 3S & 3E, and 4S & 4E. Upon closer inspection, one finds that lines are actually added to the score for 3S & 3E, and 4S & 4E, but they have zero length. Thus, they cannot be selected with the mouse cursor.

Workaround: Select the bar to which the (zero-length) note-anchored line has been added, then go to the "Properties" panel, and click on Notation > Note-anchored line. Then, in the "Text" tab, add a "Beginning text". This forces the note-anchored line to be visible, and it can then be selected with the mouse cursor. After moving the endpoints, the "Beginning text" can be removed and the line remains visible.

Expected behavior: Lines connecting the noteheads should be added for all pairs 1S & 1E, 2S & 2E, 3S & 3E, and 4S & 4E.

Supporting files, videos and screenshots

What is the latest version of MuseScore Studio where this issue is present?

4.5.2.251141402
I have also checked the nightly build (May 27, 2025), and the issue is still present

Regression

Yes, this used to work in a previous version of MuseScore 4.x

Operating system

Windows 10

Additional context

No response

Checklist

• This report follows the guidelines for reporting bugs and issues
• I have verified that this issue has not been logged before, by searching the issue tracker for similar issues
• I have attached all requested files and information to this report
• I have attempted to identify the root problem as concisely as possible, and have used minimal reproducible examples where possible

[LupusCaeruleus]

Same with glissando lines:

Looks like the current algorithm to layout such lines is

1. Draw an imaginary line that connects the two note heads. (red line)
2. Trim horizontally from both ends to get the actual end point position. (blue shade)

So, if the two notes are horizontally close enough, the line will be erased completely. A better logic might be changing the trimming area to a circle around the note head.