The ConvertMath function in MathJax/extensions/wiki2jax.js contains a strange hack which should be removed in my opinion, or at least improved and documented properly.
It transforms various hacks used to produce multiple integral signs with a circle to something, which probably should look more nicely. That it doesn't work as expected is shown on http://leuksman.com/mw/index.php/Integral, where the first formula is destroyed. If hacks in TeX produce ugly output, well, then those hacks should be avoided, not other hacks used.
Version: unspecified
Severity: normal
URL: http://leuksman.com/mw/index.php/Integral
See Also:
https://github.com/mathjax/MathJax/issues/566