Text widget shows indeterminate font and size when empty lines are selected

[its-not-nice]

Issue type

UI

Description with steps to reproduce

1. Create some text which has an empty line in the middle
2. Select it all
3. Note that the text widget popup thingy shows -- for the font and 1pt for the size.

The behaviour is correct when selecting multiple lines of text where there are no empty lines.

Supporting files, videos and screenshots

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

OS: Arch Linux, Arch.: x86_64, MuseScore Studio version (64-bit): 4.7.0-252300333, revision: github-musescore-musescore-06f977a (master 18 August 2025)

Regression

No.

Operating system

Linux

Additional context

Noticed this while testing #29018 but it's not caused by that PR.

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