From 6a513d01a10e3b35ea06c2c26aab7558fd57843f Mon Sep 17 00:00:00 2001
From: "Darryl L. Miles" <darryl.miles@darrylmiles.org>
Date: Fri, 4 Oct 2024 20:11:43 +0100
Subject: [PATCH] EFname.c: potential dereference of a null pointer

Theoretical NULL pointer deref, assumes no iteration occurs.
Seems like false positive from incorrect caller use, from
passing suffix==NULL.

SonarCloud
Access to field 'hn_parent' results in a dereference of a null pointer (loaded from variable 'prev')
https://sonarcloud.io/project/issues?open=AZJB167jNGfDNup0RjGu&id=dlmiles_magic
---
 extflat/EFname.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/extflat/EFname.c b/extflat/EFname.c
index a8ff4256..035a6d81 100644
--- a/extflat/EFname.c
+++ b/extflat/EFname.c
@@ -189,7 +189,8 @@ EFHNConcat(prefix, suffix)
 	else
 	    firstNew = new;
     }
-    prev->hn_parent = prefix;
+    if (prev)
+	prev->hn_parent = prefix;
 
     return firstNew;
 }