Strip non-graphable input characters from input. The manuals

specifically say that this is not allowed, and were it allowed, output
would be inconsistent across output media (-Tps will puke,
non-your-charset terminals will puke, etc.).

With this done, simplify check_text() to only check escapes and for
tabs.  Add in a new tab warning, too.

1 files changed, 1 insertions, 0 deletions

diff --git a/mandoc.h b/mandoc.h
index 8b3dd794..c7ac2a3e 100644
--- a/mandoc.h
+++ b/mandoc.h
@@ -39,6 +39,7 @@ enum	mandocerr {
 	MANDOCERR_LISTFIRST, /* list type must come first */
 	MANDOCERR_BADSTANDARD, /* bad standard */
 	MANDOCERR_BADLIB, /* bad library */
+	MANDOCERR_BADTAB, /* tab in non-literal context */
 	MANDOCERR_BADESCAPE, /* bad escape sequence */
 	MANDOCERR_BADQUOTE, /* unterminated quoted string */
 	MANDOCERR_NOWIDTHARG, /* argument requires the width argument */