From 366b8bc3586be54314babfe5986b86d25e5c073b Mon Sep 17 00:00:00 2001
From: Luke Dashjr <luke-jr+git@utopios.org>
Date: Thu, 11 Aug 2016 05:33:56 +0000
Subject: [PATCH] Bugfix: blkmk_init_generation*: Check cbvalue is known before
 making a new generation transaction using it

Backported from 07ce01f57a2b810ccc1fb3d4bb5f317e13496c72
---
 blkmaker.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/blkmaker.c b/blkmaker.c
index 228f91b..63e32b8 100644
--- a/blkmaker.c
+++ b/blkmaker.c
@@ -62,6 +62,12 @@ uint64_t blkmk_init_generation3(blktemplate_t * const tmpl, const void * const s
 		return 0;
 	}
 	
+	if (!tmpl->cbvalue) {
+		// TODO: Figure it out from the existing cbtxn
+		*inout_newcb = false;
+		return 0;
+	}
+	
 	*inout_newcb = true;
 	
 	if (scriptsz >= 0xfd)