\unprotect
% Line:256 of page-flt
\def\dodocomplexplacefloat[#1][#2][#3]#4%
  {\flushnotes
   \flushsidefloats % here !
   \ifsomefloatwaiting
     % this was \checkwaitingfloats spread all over
     \doifinsetelse\v!always{#2}
       {\showmessage\m!floatblocks5\empty}
       {\expanded{\doifcommonelse{#2}{\flushfloatslist}}\doflushfloats\donothing}%
     % but which should be done before using box \floatbox
   \fi
   \ifmargeblokken
     \doifinset\v!margin{#2}\endgraf
   \fi
   \global\insidefloattrue
   \begingroup % **
   \ifmargeblokken
     \doifinset\v!margin{#2}{\hsize\@@mbwidth}%
   \fi
   \the\everyinsidefloat
   \let\@@extrafloat\empty
   \presetmorefloatvariables{#2}%
   \dowithnextboxcontent % better a \the\everyfloattoks
     {\setlocalfloathsize
      \floatparameter\c!inner
      \fuzzysnappingfalse
      \postponenotes} % new
     {\doifsomething{\floatparameter\c!criterium}
        {\ifdim\wd\nextbox>\floatparameter\c!criterium\relax
           \edef\forcedfloatmethod{\executeifdefined{\??fl\currentfloat\c!fallback}\v!here}%
         \fi}%
       \xdocompletefloat{#1}{#3}{#1}{#2}{#1}{#4}% ** not yet done
       % we need to carry over the par because of side floats
      \doifnotinset\v!text{#2}{\carryoverpar\endgroup}%
      \global\sidefloatdownshift \zeropoint
      \global\sidefloatextrashift\zeropoint
      \ifparfloat
        \doifinset\v!reset{#2}\forgetsidefloats
        \doinhibitblank
      \fi% better move this to side floats
     %AM:Added
     \nonoindentation
     \dochecknextindentation{\??fl\currentfloat}%
     \dorechecknextindentation}
     \vbox}

% Line:2599 of page-flt
\def\sometopfloat [#1]{\someelsefloat[#1]}
\protect

% Test: Try with and without the patch

\setupindenting[big,yes]

\setupfloat [figure] [indentnext=auto]

\starttext

\section {Test}
\placefigure[top]{top}{}
\input knuth

\input tufte

\placefigure[bottom]{top}{}

\input tufte

\stoptext