Longmin Wang 写道: Hi Longmin,
It works fine here with the latest beta and luatex 0.40. You may try to delete luatex-cache and regenerate it.
It solves the problem, thanks. I find another problem with the example in my previous email. I changed the example a little bit. Example: \startuseMPgraphic{mpos:par:columnset:textuline} \iftracepositions show_multi_pars \else draw_multi_pars \fi ; path p ; p := boundingbox currentpicture ; currentpicture := currentpicture shifted (0,0.3*StrutDepth) ; setbounds currentpicture to p ; \stopuseMPgraphic \definetextbackground [underline] [location=text, alternative=1, mp=mpos:par:columnset:textuline, background=, frame=off] \starttext \underline{blurblur} \underline{blurblur} \underline{blurblur} \underline{blurblur} \stoptext The vertical positions of underlines are not stable. See the attached PDF file. Best wishes, Wei-Wei