Help with a bug in nroff sought

[cosell at bbn-labs-b.ARPA]

From:  Bernie Cosell <cosell at bbn-labs-b.ARPA>

I've tried this on our local nroff wizards and they don't know anything about
it - anyone out there ever seen this bug or maybe even fixed it?

Thanks
   /Bernie

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Date: Mon, 30 Apr 84 14:03:21 EDT
From: Bernie Cosell <cosell at bbn-labs-b>
Subject: bug explanation sought
To: nroff at bbn-labs-b

In trying to debug a bunch of macros, I was going nuts because I apparently
blundered into a bug in nroff.  Can anyone confirm just exactly what this bug
is and how it works?

Consider:
    .de X
    .so /etc/motd
    .tm it never gets here
    ..


    .X

When you place the call to macro X as the VERY LAST line in the input file, it
never returns from the .so and so DOESN'T get to the .tm -- if the call occurs
anywhere else in the source file, it works as you would expect and the .tm,
desipite what it says, does get done.  It seems clear that there is something a
little odd going on in its figuring out where to pick things up when you pop
out of .so - if the main source file is at EOF, that apparently prevents the
pop from being able to figure out where to resume the macro it was in....

Can anyone shed any light on this?

Thanks
   /Bernie

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