groff's -mm macros have Moved the Footer in version 1.18.

[Ralph Corderoy]

Binary package hint: groff

The footer printed with the -mm macros has changed position between
groff versions 1.17.2 and 1.18 present in Ubuntu 5.04. This is a pain
as turning troff documents written before 5.04 into PostScript no longer
produces the same results despite the document source not changing.
Ubuntu actually provides version 1.18.1.1-7, but it's present in that
too and, as of the time of writing, groff CVS.

Here's a document that shows the problem.

    .\" groff -mm -ma4 footermoves.tr >footermoves.ps
    .\"
    .PGFORM 21c-2i 29.7c-1i 1i 1
    .PH "'hl'hc'hr'"
    .PF "'fl'fc'fr'"
    .\"
    .S +1
    .P
    Footer not in a constant place across groff versions.

If the `.S +1' is commented out the problem doesn't occur.

The non-postprocessed output can be obtained by using -Z: groff -Z -mm
-ma4 footermoves.tr

Here's the differences between the two outputs.

    --- footermoves.1.17.2.out 2006-05-03 14:32:20.958257072 +0100
    +++ footermoves.1.18.out 2006-05-03 14:32:21.034245520 +0100
    @@ -42,10 +42,10 @@
     H264467
     tersions.
     n13000 0
    -V730889
    +V735889
     H523275
     n13000 0
    -V743889
    +V748889 [Vertical position different here before printing `fl'.]
     H72000
     Cfl
     h221364
    @@ -53,7 +53,7 @@
     h214038
     tfr
     n13000 0
    -V756889
    +V761889
     H523275
     n13000 0
     x trailer

[Ralph Corderoy (ralph-inputplus)]

Other things are moving on the page too. Take this simple test case.

    .\" groff -t -ma4 -mm simple.tr >simple.ps
    .\"
    .DS
    foo
    .DE
    .DS
    bar
    .DE

The location of `bar' is vertically lower with 1.18 compared to 1.17.2.

Again, from the differences in the definition of DS, it looks like unit
changes for header and footer margins may be the cause.

[Ralph Corderoy (ralph-inputplus)]

A workaround for the .DS/.DE/.DS/.DE example above where `bar' is lower
is to add a `.sp -0.5v' after the first .DE when using the more recent,
broken, groff.