How do I find out the maximum extent that a morph can be set to, without this impacting the current extent of its owner morph?

How to I prevent an embedded TextMorph from wrapping the text I enter  
into it if said text exceeds the current bounds of that morph,  
despite the fact that its much-larger owner gives it ample expansion  
room via the "hResizing: #spaceFill" selector?

I've tried a gazillion (minus one?) layout, autoFit, and wrapFlag  
setting combos to no avail: that little son-of-a-... morph keeps  
wrapping its text as soon as entry has exceeded the current bounds.

Thanks, again
Alex