log: Add check for return value.

For some reason I got a segfault in gdb here. Make sure it works
correctly.

1 files changed, 4 insertions, 0 deletions

diff --git a/src/log.c b/src/log.c
index 9f6b5a4a..a72dd412 100644
--- a/src/log.c
+++ b/src/log.c
@@ -215,6 +215,10 @@ ssh_logging_callback ssh_get_log_callback(void) {
  */
 void *ssh_get_log_userdata(void)
 {
+    if (ssh_log_userdata == NULL) {
+        return NULL;
+    }
+
     return ssh_log_userdata;
 }