If `Ns' is specified on its own line, it should be ignored. This is

shitty groff behaviour.  Do the same, but raise a warning to this
effect.  This from a TODO noted by schwarze@.

1 files changed, 1 insertions, 0 deletions

diff --git a/main.c b/main.c
index 7e4bbb3a..1bf8712c 100644
--- a/main.c
+++ b/main.c
@@ -146,6 +146,7 @@ static	const char * const	mandocerrs[MANDOCERR_MAX] = {
 	/* related to macros and nesting */
 	"skipping obsolete macro",
 	"skipping paragraph macro",
+	"skipping no-space macro",
 	"blocks badly nested",
 	"child violates parent syntax",
 	"nested displays are not portable",