Allow a NULL mmsg passed to libmandoc.

1 files changed, 2 insertions, 1 deletions

diff --git a/read.c b/read.c
index 27aaf8d2..bc7d2071 100644
--- a/read.c
+++ b/read.c
@@ -740,7 +740,8 @@ mandoc_msg(enum mandocerr er, struct mparse *m,
 	if (level < m->wlevel)
 		return;
 
-	(*m->mmsg)(er, level, m->file, ln, col, msg);
+	if (m->mmsg)
+		(*m->mmsg)(er, level, m->file, ln, col, msg);
 
 	if (m->file_status < level)
 		m->file_status = level;