[Qemu-block] [PATCH v2 1/2] block/replication: prefect the logic to acquire 'top_id'

[Changlong Xie]

Only g_strdup(top_id) if 'top_id' is not NULL, although there
is no memory leak here

Signed-off-by: Changlong Xie <xiecl.f...@cn.fujitsu.com>
---
 block/replication.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/block/replication.c b/block/replication.c
index 3bd1cf1..5b432d9 100644
--- a/block/replication.c
+++ b/block/replication.c
@@ -104,11 +104,11 @@ static int replication_open(BlockDriverState *bs, QDict 
*options,
     } else if (!strcmp(mode, "secondary")) {
         s->mode = REPLICATION_MODE_SECONDARY;
         top_id = qemu_opt_get(opts, REPLICATION_TOP_ID);
-        s->top_id = g_strdup(top_id);
-        if (!s->top_id) {
+        if (!top_id) {
             error_setg(&local_err, "Missing the option top-id");
             goto fail;
         }
+        s->top_id = g_strdup(top_id);
     } else {
         error_setg(&local_err,
                    "The option mode's value should be primary or secondary");
-- 
1.9.3