From f271c6916469c0054c143adb4cee0588866a2a61 Mon Sep 17 00:00:00 2001
From: NIIBE Yutaka <gniibe@fsij.org>
Date: Fri, 27 Aug 2021 16:55:25 +0900
Subject: [PATCH] common: Fix put_membuf.

* common/membuf.c (put_membuf): Allow NULL for the second arg.

--

There has been such a use case in keybox-blob.c.

Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>
---
 common/membuf.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/common/membuf.c b/common/membuf.c
index 18a971d54..009fbc336 100644
--- a/common/membuf.c
+++ b/common/membuf.c
@@ -111,7 +111,10 @@ put_membuf (membuf_t *mb, const void *buf, size_t len)
         }
       mb->buf = p;
     }
-  memcpy (mb->buf + mb->len, buf, len);
+  if (buf)
+    memcpy (mb->buf + mb->len, buf, len);
+  else
+    memset (mb->buf + mb->len, 0, len);
   mb->len += len;
 }