[XeTeX] XeTeX infinite loop [][][][][][] bug - possible fix

[Dalyoung]

Dear all,

I got another case of infinite loop [][][][]... even though I set  
\hfuzz things.(but not changed mem variables in texmf.cnf)
Here is a code.
The error occurs because there is a blank in [ topview]{top view}.
After I edited it as [topview](remove the space before topview), it  
worked fine.

For test, I added memory settings in texmf.cnf which was suggested by  
Jonathan, Hans and Adam, and delete \hfuzz things from the code.
Then there is no error messages in the terminal even if I made a blank  
as [ topview].
However, there is no graphic of topview but many repeated captions.

Hence I think that it should be the exact name only in the first [] of  
\externalfigure.

Is this the general case?

Regards,

Dalyoung

*************
\useexternalfigure [topview][coins1] [width=.4\textwidth]
\useexternalfigure [frontview][coins2] [width=.4\textwidth]

\tolerance 1414
\hbadness=1414
\emergencystretch 1.5em
\hfuzz=.03pt
\widowpenalty=10000
\vfuzz \hfuzz

\starttext

\placefigure
  [here, nonumber] [] { }
{\startcombination[2*1]
	{\externalfigure[ topview]}{top view} %%there is a blank in [ topview]
  	{\externalfigure[frontview]}{front view}
\stopcombination}

\stoptext
***********************
color          : system rgb is local activated

Underfull \hbox (badness 3930) in paragraph at lines 16--16
  [][] \*12ptmmmr* top view []  
[][][][][][][][][][][][][][][][][][][][][][][][][
][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][ 
][][][]
******************************