Subject: [PATCH 2/3] Fix zero key_thread_attempt_id case

--- a/lib/log.c
+++ b/lib/log.c
@@ -38,7 +38,7 @@
 	char buffer[ATTEMPT_ID_SIZE + 1];
 	char *prefixed_msg = NULL;
 
-	attempt_id = pthread_getspecific(key_thread_attempt_id);
+	attempt_id = key_thread_attempt_id ? pthread_getspecific(key_thread_attempt_id) : 0;
 	if (attempt_id) {
 		int len = sizeof(buffer) + 1 + strlen(msg) + 1;