comment #1:

> the "3usekeeps" hack

implemented as a repsonse to bug #57665

Confirmed; thanks for the report.

The version of the ascii(7) man page in Linux man-pages 5.10 on my Debian system did not reproduce this behavior, but the one from my Git checkout of its project did.

I'm attaching a bespoke reproducer.

The problem appears to be that even with continuous rendering on, a notional page length of 11 inches remains in place, extended in places by certain macros a line at a time.  However, when we start a table with `TS`, that macro can't have any idea how long the table will ultimately be.

Thus, if the table should happen to be long enough to cross a "page" boundary, the vertical line (which is always drawn from the bottom up in GNU tbl) is of the wrong length (and starts from the wrong place, too).

Here's a patch that appears to solve the problem.  It's a bit of a hack (but so is what we do for line length in HTML output.)

Before committing, which might wait until after 1.23.0 final anyway, I'd like to see if this hack obviates the need for the "3usekeeps" hack which I also put in place for managing tbl tables in man pages when continuous rendering.

And ultimately, both of those hacks as well as a lot of tedium in man(7) and mdoc(7) might be obviated if we proceed with my plans in bug #63587.

$ git di
diff --git a/tmac/an.tmac b/tmac/an.tmac
index 0d540fbcb..df92dfa27 100644
--- a/tmac/an.tmac
+++ b/tmac/an.tmac
@@ -1203,6 +1203,10 @@ contains unsupported escape sequence
 .  \" If continuous rendering, tell tbl not to use keeps.
 .  ie \\n[cR] .nr 3usekeeps 0
 .  el         .nr 3usekeeps 1
+.  if \\n[cR] \{\
+.    nr an*saved-trap-distance \\n[.t]
+.    pl +1000i
+.  \}
 .  if \\n[an*is-output-html] \{\
 .    nr an-TS-ll \\n[.l]
 .    ll 1000n
@@ -1218,6 +1222,10 @@ contains unsupported escape sequence
 .de1 TE
 .  HTML-IMAGE-END
 .  if \\n[an*is-output-html] .ll \\n[an-TS-ll]u
+.  if \\n[cR] \{\
+.    pl (u;\\n[nl] + \\n[an*saved-trap-distance])
+.    rr an*saved-trap-distance
+.  \}
 .  if !r TW .if !\\n[an-was-tbl-failure-reported] \{\
 .    ds an-msg tbl preprocessor failed, or it or soelim was not run;\"
 .    as an-msg " table(s) likely not rendered\"

Feel free to apply this to your local derivative of groff; please report any collateral problems arising from it.

(file #54526)