mdoc(7) already uses the mandoc(1) -Ios argument in the footer line

when .Os has no argument, so do the same for man(7) when .TH has less
than four arguments; there is no reason to treat both differently.
Issue found following a question from Thomas Klausner <wiz at NetBSD>.

1 files changed, 6 insertions, 3 deletions

diff --git a/read.c b/read.c
index 9b266090..acf1c1e5 100644
--- a/read.c
+++ b/read.c
@@ -298,7 +298,8 @@ choose_parser(struct mparse *curp)
 	/* Fall back to man(7) as a last resort. */
 
 	if (NULL == curp->pman)
-		curp->pman = man_alloc(curp->roff, curp,
+		curp->pman = man_alloc(
+		    curp->roff, curp, curp->defos,
 		    MPARSE_QUICK & curp->options ? 1 : 0);
 	assert(curp->pman);
 	curp->man = curp->pman;
@@ -696,7 +697,8 @@ mparse_end(struct mparse *curp)
 			curp->mdoc = curp->pmdoc;
 		else {
 			if (curp->pman == NULL)
-				curp->pman = man_alloc(curp->roff, curp,
+				curp->pman = man_alloc(
+				    curp->roff, curp, curp->defos,
 				    curp->options & MPARSE_QUICK ? 1 : 0);
 			curp->man = curp->pman;
 		}
@@ -940,7 +942,8 @@ mparse_alloc(int options, enum mandoclevel wlevel, mandocmsg mmsg,
 		    curp->roff, curp, curp->defos,
 		    curp->options & MPARSE_QUICK ? 1 : 0);
 	if (curp->options & MPARSE_MAN)
-		curp->pman = man_alloc(curp->roff, curp,
+		curp->pman = man_alloc(
+		    curp->roff, curp, curp->defos,
 		    curp->options & MPARSE_QUICK ? 1 : 0);
 
 	return(curp);