I have more information on my upright math problem, but still no fix. Here is my new MWE: \starttext \showotfcomposition{bodyfont}{}{a=b \m{a=b}} \stoptext I may not be using this debugging command correctly, but it is returning useful information. The result is correct and the same in TeX Live 2021 MkIV and in the most recent LMTX. Notice that glyphs selected for “a” and “b” are different in the text and math: LuaTeX, Version 1.13.2 (TeX Live 2021) ConTeXt ver: 2021.03.05 19:11 MKIV fmt: 2021.5.11
a=b 𝑎 = 𝑏 U+61:a U+3D:= U+62:b [glue][math] U+1D44E:𝑎 [glue] U+3D:= [glue] U+1D44F:𝑏 [math]
ConTeXt ver: 2021.05.25 18:03 LMTX fmt: 2021.5.25
a=b 𝑎 = 𝑏 U+61:a U+3D:= U+62:b [glue][math] U+1D44E:𝑎 [glue] U+3D:= [glue] U+1D44F:𝑏 [math]
However, it is wrong in the most recent MkIV. The glyphs for “a” and “b” are the same in the text and math, even though the switch to math is recognized. (This switch is also evident in the pdf output. There is no space around the “=“ in the text, but it is correct for the math.) LuaTeX, Version 1.13.0 (TeX Live 2021) ConTeXt ver: 2021.05.25 18:03 MKIV fmt: 2021.5.25
a=ba=b U+61:a U+3D:= U+62:b [glue][math] U+61:a [kern][glue] U+3D:= [glue] U+62:b [math]
What could cause MkIV to select upright glyphs when it knows it is typesetting math? One difference is the version of LuaTeX. Could this need to be updated? Gavin