texmath-0.6.7: tests/writers/munderover-05.tex
\underset{\phantom{\mathrm{fail}}}{\overset{\phantom{\mathrm{fail}}}{\mathrm{\_\ \ baseline\ \_\ }}}=\mathrm{\_\ \ baseline\ \_\ }\underset{\phantom{\mathrm{fail}}}{\overset{\phantom{\mathrm{fail}}}{\mathrm{\_\ \ baseline\ \_\ }}}=\mathrm{\_\ \ baseline\ \_\ }