RECTO_VERSO uses wrong margins

[Samuel Stoddard]

Hi!  I'm having a problem using the .RECTO_VERSO macro, namely that for all
of the verso pages the left margin is about 3 inches more than it should
be, and the page content is shifted off the physical dimensions of the
page.  I don't know if this is actually about margins, though -- it might
be about paper sizes (I am using 6 in x 9 in paper size, which is about
432p x 648p).

To be clear, page 1 of this 2-page test document looks fine, but page 2
shows a block of text that appears to be in the correct dimensions but
shifted right by about 3 inches, so that the right portion of the text
block is invisible (rendered outside the page).

Any ideas?  Thanks so much in advance.

-- Sam.

Here is everything I'm using to reproduce the problem:

==== Versions ====

groff version: 1.22.4
mom version: 2.4

==== Commands I use to generate a PDF: ====

groff -mom -dpaper=6i,9i -P-p9i,6i < test.t > test.ps

/usr/bin/ps2pdf -dDEVICEWIDTHPOINTS=432 -dDEVICEHEIGHTPOINTS=648
-dPDFFitPage - - < test.ps > test.pdf

==== Things I have tried to fix it: ====

It's weird that -dpaper= and -P-p take the page dimensions in the opposite
order, so just for fun I've tried using all permutations of width/height
specification, but all of these cause worse problems.

I've also tried mucking with the ps2pdf arguments and using ps2pdf12,
ps2pdf13, and ps2pdf14 instead, but none of that seems to change anything.

==== Source "test.t" File: ====

.PRINTSTYLE TYPESET
.PAGEWIDTH 6i
.PAGELENGTH 9i
.T_MARGIN .87i
.B_MARGIN 1i
.L_MARGIN .5i
.R_MARGIN .75i
.RECTO_VERSO

.FAMILY P
.FT R
.PT_SIZE 12
.LS 14

.DOC_COVERS OFF
.COVERS OFF
.DOCHEADER OFF
.HEADERS OFF
.FOOTERS OFF

.START
1: Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod
tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim
veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea
commodo consequat. Duis aute irure dolor in reprehenderit in voluptate
velit esse cillum dolore eu fugiat nulla pariatur.
.SPACE 1v
2: Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod
tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim
veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea
commodo consequat. Duis aute irure dolor in reprehenderit in voluptate
velit esse cillum dolore eu fugiat nulla pariatur.
.NEWPAGE
3: Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod
tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim
veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea
commodo consequat. Duis aute irure dolor in reprehenderit in voluptate
velit esse cillum dolore eu fugiat nulla pariatur.
.SPACE 1v
4: Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod
tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim
veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea
commodo consequat. Duis aute irure dolor in reprehenderit in voluptate
velit esse cillum dolore eu fugiat nulla pariatur.
.MCX