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/mandoc.h b/mandoc.h
index 61a1f5ad..704ec745 100644
--- a/mandoc.h
+++ b/mandoc.h
@@ -68,6 +68,7 @@ enum	mandocerr {
 	/* related to macros and nesting */
 	MANDOCERR_MACROOBS, /* skipping obsolete macro */
 	MANDOCERR_IGNPAR, /* skipping paragraph macro */
+	MANDOCERR_IGNNS, /* skipping no-space macro */
 	MANDOCERR_SCOPENEST, /* blocks badly nested */
 	MANDOCERR_CHILD, /* child violates parent syntax */
 	MANDOCERR_NESTEDDISP, /* nested displays are not portable */