[WinCairo] fonts/use-typo-metrics-1.html is failing as ImageOnlyFailure

• Component: Platform
• Status: NEW ---

[Fujii Hironori]

[WinCairo] fonts/use-typo-metrics-1.html is failing as ImageOnlyFailure

It seems that GetOutlineTextMetrics doesn't preserve OS/2 USE_TYPO_METRICS flag for OpenType fonts.
fonts/lineheight5000-typolineheight2300.woff seems a WOFF generated from a OpenType font.
If I convert lineheight5000-typolineheight2300.woff to TTF, and converted back to WOFF, the test case will pass.

Firefox seems using HarfBuzz to get OS/2 section on Windows.

[Frédéric Wang (:fredw)]

I wonder if the tools you use to convert to TTF and WOFF again might do extra sanitisation changes. 

Are you able to use the script to generate a TTF and then load directly the .ttf file with @font-face rule?

[Fujii Hironori]

I created lineheight5000-typolineheight2300.ttf.
I confirmed USE_TYPO_METRICS flag is preserved, the test can pass.

diff --git a/mathml/tools/use-typo-lineheight.py b/mathml/tools/use-typo-lineheight.py
index 9768979f48..c98020868b 100644
--- a/mathml/tools/use-typo-lineheight.py
+++ b/mathml/tools/use-typo-lineheight.py
@@ -44,7 +44,7 @@ font.os2_windescent_add = False
 
 font.os2_use_typo_metrics = True
 
-path = "../../fonts/math/lineheight%d-typolineheight%d.woff" % (winHeight, typoLineHeight)
+path = "../../fonts/math/lineheight%d-typolineheight%d.ttf" % (winHeight, typoLineHeight)
 print("Generating %s..." % path, end="")
 font.generate(path)
 if font.validate() == 0:

[Fujii Hironori]

280480@main added the USE_TYPO_METRICS support for some fonts for Windows port.
However, fonts/use-typo-metrics-1.html is still failing. This ticket keeps tracking the issue.