In bug 947650, we made Unix platforms use typo metrics when the USE_TYPO_METRICS flag is set or when a MATH table is present. For Windows, this was done in bug 598900 but we relied only on the USE_TYPO_METRICS flags. Today, the only remaining OpenType MATH font that misses the USE_TYPO_METRICS flag is STIX (and this issue is fixed in the STIX version in developement). So we will eventually be able to remove the test for a MATH table and only rely on the USE_TYPO_METRICS flags on all platforms.
Created attachment 8653346 [details] [diff] [review] Patch