From ef7072c55061398de01299d9bc02d3a179fcb3bc Mon Sep 17 00:00:00 2001
From: Ingo Schwarze <schwarze@openbsd.org>
Date: Sat, 25 Oct 2014 15:06:30 +0000
Subject: Fix a NULL pointer dereference reported by Theo Buehler <theo at math
 dot ethz dot ch> on tech at openbsd: Do not attempt to parse empty equations.

---
 eqn.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/eqn.c b/eqn.c
index 2e77c484..ebe0c3e2 100644
--- a/eqn.c
+++ b/eqn.c
@@ -684,7 +684,9 @@ eqn_parse(struct eqn_node *ep, struct eqn_box *parent)
 	char		 sym[64];
 	const char	*start;
 
-	assert(NULL != parent);
+	assert(parent != NULL);
+	if (ep->data == NULL)
+		return(-1);
 
 next_tok:
 	tok = eqn_tok_parse(ep, &p);
-- 
cgit