Summary
On JDK 25, both \Omega and \varOmega reserve their expected layout space but paint no visible pixels.
This affects JLaTeXMath 1.0.7 and the current 1.0.8-SNAPSHOT branch. It is also visible in consumers such as PlantUML when they run on a recent JDK.
Root cause
JLaTeXMath maps both uppercase Omega symbols to character slot 173:
<SymbolMapping name="Omega" ch="173" fontId="jlm_cmr10"/>
<SymbolMapping name="varOmega" ch="173" fontId="jlm_cmmi10"/>
Decimal 173 is Unicode U+00AD SOFT HYPHEN. Since OpenJDK change JDK-8208377, default-ignorable characters are mapped to INVISIBLE_GLYPH_ID even when the custom font contains a glyph for that code point.
The XML font metrics still supply a non-zero width and height, so the formula occupies space, but AWT paints no glyph.
Reproduction
A direct TeXIcon rendering test on JBR 25.0.3 and OpenJDK 26 produces zero non-transparent pixels for both commands:
TeXIcon icon = new TeXFormula("\\Omega")
.createTeXIcon(TeXConstants.STYLE_DISPLAY, 40);
BufferedImage image = new BufferedImage(
icon.getIconWidth(),
icon.getIconHeight(),
BufferedImage.TYPE_INT_ARGB);
icon.paintIcon(null, image.createGraphics(), 0, 0);Proposed fix
Move the internal Omega glyph mapping from slot 173 to unused slot 172, and update:
jlm_base.map.xml- the
jlm_cmr10 and jlm_cmmi10 XML metrics
- the Unicode cmap entries in both TTF files
- regression tests that assert both symbols paint visible pixels
Literal U+00AC input is already mapped to \lnot by TeXFormulaSettings.xml, so using slot 172 internally does not change that input behavior.
Verification
- Full
jlatexmath module tests: 11 tests, 0 failures
- JBR 25.0.3 + PlantUML 1.2026.2 smoke test: both
\Omega and \varOmega render visibly
A git-format patch is attached.
jlatexmath-omega-jdk25.patch.zip
Summary
On JDK 25, both
\Omegaand\varOmegareserve their expected layout space but paint no visible pixels.This affects JLaTeXMath 1.0.7 and the current 1.0.8-SNAPSHOT branch. It is also visible in consumers such as PlantUML when they run on a recent JDK.
Root cause
JLaTeXMath maps both uppercase Omega symbols to character slot 173:
Decimal 173 is Unicode U+00AD SOFT HYPHEN. Since OpenJDK change JDK-8208377, default-ignorable characters are mapped to
INVISIBLE_GLYPH_IDeven when the custom font contains a glyph for that code point.The XML font metrics still supply a non-zero width and height, so the formula occupies space, but AWT paints no glyph.
Reproduction
A direct
TeXIconrendering test on JBR 25.0.3 and OpenJDK 26 produces zero non-transparent pixels for both commands:Proposed fix
Move the internal Omega glyph mapping from slot 173 to unused slot 172, and update:
jlm_base.map.xmljlm_cmr10andjlm_cmmi10XML metricsLiteral U+00AC input is already mapped to
\lnotbyTeXFormulaSettings.xml, so using slot 172 internally does not change that input behavior.Verification
jlatexmathmodule tests: 11 tests, 0 failures\Omegaand\varOmegarender visiblyA git-format patch is attached.
jlatexmath-omega-jdk25.patch.zip