Error when dissecting large objects

Reproduction:
```
   load 'debug/dissect'
   dissect 'i.200'
error in paint
domain error
|domain error: cd
|       glrect 0 0 1 1+"1^:(-.IFQT),"2|."1 y
```
Versions:
 - `debug/dissect`: 4.6.40 
 - `j9`: j903-beta-j1
 - `qtide`: `f4b46fec`