Fix incorrect handling of line-height CSS in HTML → PDF conversion

[RadekWikturna]

Description of the new Feature/Bugfix

When parsing HTML with a span styled with line-height (e.g., <span "line-height:115%">), the generated Paragraph in OpenPDF 1.3.x computed the multiplied leading incorrectly, resulting in overlapping lines (see attached PDF file).

paragraph.getLeading()           = 0.0
paragraph.getMultipliedLeading() = 0.138  // much too small
paragraph.getTotalLeading()      ≈ 1.656  // causes overlapping lines in the PDF

Expected behavior:

For font size 12pt and line-height:115%, the total leading should be ≈ 13.8pt (12 × 1.15).

Cause:

FactoryProperties.insertStyle, line 383 handles line-height in percentage (by dividing by 100) although the percentage handling is done already in Markup.parseLength(String string, float actualFontSize), line 553.
The problem was most likely introduced by: #1059 When converting HTML to PDF, font size specified in % is interpreted as pixels

Solution:

Adjusted FactoryProperties.insertStyle - removed handling line-height in percentage.

Added a JUnit test (testLineHeightPercentage) that parses a small HTML snippet with line-height:115% and asserts that Paragraph.getTotalLeading() matches the expected value.

Unit-Tests for the Bugfix

• [x ] Unit-Tests added to reproduce the bug

Compatibilities Issues

None

Your real name

Radek Wikturna

Testing details

Any other details about how to test the new feature or bugfix?

Line Height Percentage.pdf

[sonarqubecloud]

Quality Gate failed

Failed conditions
47 Security Hotspots
B Maintainability Rating on New Code (required ≥ A)
D Security Rating on New Code (required ≥ A)
D Reliability Rating on New Code (required ≥ A)

See analysis details on SonarQube Cloud

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[RadekWikturna]

I wonder if anyone can have a look, so that the pull request could be accepted.

I've described the issue in detail, including the cause.
I've fixed the problem (basically removed a few lines)
I've written a JUnit test covering this problem

All tests pass.

Note: Some SonarCloud Code Analysis and Codacy Code Analysis report some problem - but NOT in the new code but elsewhere.

[RadekWikturna]

I'm rather disappointed that there's no activity towards merging this fix. My previous 3 pull requests were merged pretty fast and this one is just waiting. Can I do anything to make it happen? @asturio, can you help?