Created attachment 70977 [details] Example of stretching for msup, msup, msubsup msup/msup need to share the same implementation with msubsup so that they stretch operators.
Created attachment 232657 [details] testcase 2 The current testcase is invalid. integral is not stretchy by default per the op dict, so it should not stretch. I attach a correct testcase testing either - that integrals in display style are drawn larger (they are largeop per the op dict) - integrals with stretchy="true" next to a tall <mspace/> stretch. This works on Linux (and assumes that Latin Modern fonts are installed). Anyway, the bug was about inconsistencies between msubsup/msub/msup, which should not happen anymore since they all use a RenderMathMLScripts.