From 600e69b46149872c279c153dc7a757106c64cc03 Mon Sep 17 00:00:00 2001
From: Werner Koch <wk@gnupg.org>
Date: Thu, 5 May 2022 09:04:28 +0200
Subject: scd:openpgp: Fix a segv for cards supporting unknown curves.

* common/openpgp-oid.c (get_keyalgo_string): Do not strdup NULL.
--

Cherry pick 2.4/master commit of:
	385f4841330e277949ddf2f13939b97481d2d29c

GnuPG-bug-id: 5963
---
 common/openpgp-oid.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/common/openpgp-oid.c b/common/openpgp-oid.c
index 9d8b2d351..1e5dc4a3a 100644
--- a/common/openpgp-oid.c
+++ b/common/openpgp-oid.c
@@ -580,7 +580,7 @@ get_keyalgo_string (enum gcry_pk_algos algo,
       for (i=0; i < keyalgo_strings_used; i++)
         {
           if (keyalgo_strings[i].algo == algo
-              && keyalgo_strings[i].curve
+              && keyalgo_strings[i].curve && curve
               && !strcmp (keyalgo_strings[i].curve, curve))
             return keyalgo_strings[i].name;
         }
@@ -594,7 +594,7 @@ get_keyalgo_string (enum gcry_pk_algos algo,
       else
         name = xasprintf ("E_error");
       nbits = 0;
-      curvebuf = xstrdup (curve);
+      curvebuf = curve? xstrdup (curve) : NULL;
     }
   else
     {
-- 
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