[Groff] .ch request query

[Dean Allen Provins]

Hello:

I had reason to place two traps at the same location, and as ".wh" at
the same place causes the second to overwrite the first (or so I
understood), I created the second at another trap location, and tried to
"move" it to the first.  This seemed not to work with groff version
1.19.  Example code follows, and the postscript output is attached.  

Groff was executed as:

        groff -Tps -ms test50.s > a.ps

What have I done wrong?

Regards,

Dean

-------------sample code--------
.LP
.wh 2i x
.wh 3i y
.ch y 2i
.de x
.br
.nr where \\n[.h]/72
macro x was invoked at \\n[where]
.br
..
.de y
.br
.nr where \\n[.h]/72
macro y was invoked at \\n[where]
.br
..
this is line 1
.br
this is line 2
.br
this is line 3
.br
this is line 4
.br
this is line 5
.br
this is line 6
.br
this is line 7
.br
this is line 8
.br
this is line 9
.br
this is line 10
.br
this is line 11
.br
this is line 12
.br
this is line 13
.br
this is line 14
.br
this is line 15

-- 
                                Dean Provins 
                          address@hidden
                  KeyID at at pgpkeys.mit.edu:11371: 0x9643AE65

test50.ps
Description: PostScript document