Do not read one element past the end of the static const termacts array.

Bug found by Sevan Janiyan <venture37 at geeklan dot co dot uk>
who ran the OpenBSD mandoc test suite on Ubuntu on POWER8 (sic!)
and reported that mdoc/Sh/before.in failed in -Tman mode.
If that isn't power testing, i don't know...

1 files changed, 2 insertions, 1 deletions

diff --git a/man_term.c b/man_term.c
index e4f106b9..a2f32c7e 100644
--- a/man_term.c
+++ b/man_term.c
@@ -822,7 +822,8 @@ pre_SH(DECL_ARGS)
 
 		do {
 			n = n->prev;
-		} while (n != NULL && termacts[n->tok].flags & MAN_NOTEXT);
+		} while (n != NULL && n->tok < MAN_MAX &&
+		    termacts[n->tok].flags & MAN_NOTEXT);
 		if (n == NULL || (n->tok == MAN_SH && n->body->child == NULL))
 			break;