From cd6e167982615cdf6cc529c8b15d4b84c0058fa3 Mon Sep 17 00:00:00 2001
From: Greg King <gregdk@users.sf.net>
Date: Fri, 4 Jan 2019 02:29:17 -0500
Subject: [PATCH] Fixed a duplicate-label test.

Don't call strcmp() if either argument is NULL.
---
 src/da65/labels.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/da65/labels.c b/src/da65/labels.c
index 6aa7f38cf..97e195ebf 100644
--- a/src/da65/labels.c
+++ b/src/da65/labels.c
@@ -92,7 +92,9 @@ static void AddLabel (unsigned Addr, attr_t Attr, const char* Name)
         ** have a name (you guessed that, didn't you?).
         */
         if (ExistingAttr == Attr &&
-            ((Name == 0 && SymTab[Addr] == 0) || strcmp (SymTab[Addr], Name) == 0)) {
+            ((Name == 0 && SymTab[Addr] == 0) ||
+             (Name != 0 && SymTab[Addr] != 0 &&
+             strcmp (SymTab[Addr], Name) == 0))) {
             return;
         }
         Error ("Duplicate label for address $%04X: %s/%s", Addr, SymTab[Addr], Name);