From 635bf5a6b2f5ff87095f4350cea6f6f4e192d14f Mon Sep 17 00:00:00 2001
From: James Keast <jkeast@blackberry.com>
Date: Fri, 10 Feb 2023 15:24:15 -0400
Subject: [PATCH] setopt: Address undefined behaviour by checking for null

This addresses undefined behaviour found using clang's UBsan:

curl/lib/setopt.c:177:14: runtime error: applying non-zero offset 1 to null pointer
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior curl/lib/setopt.c:177:14 in

Closes #10472
---
 lib/setopt.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/setopt.c b/lib/setopt.c
index b8c639847a..b8fa1b89e6 100644
--- a/lib/setopt.c
+++ b/lib/setopt.c
@@ -174,7 +174,7 @@ static CURLcode protocol2num(const char *str, curl_prot_t *val)
 
       *val |= h->protocol;
     }
-  } while(str++);
+  } while(str && str++);
 
   if(!*val)
     /* no protocol listed */
-- 
2.47.2