From 0f1d6c627151d0a92ee9fa2a69e99f24f7f26616 Mon Sep 17 00:00:00 2001
From: Stephen Akridge <stephen@solana.com>
Date: Tue, 5 Mar 2019 11:17:59 -0800
Subject: [PATCH] Check for no entries left in blocktree in a given slot

There may not be ENTRIES_PER_SEGMENT entries a slot, if so
then we will hang waiting for more.
---
 core/src/chacha_cuda.rs | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/core/src/chacha_cuda.rs b/core/src/chacha_cuda.rs
index 05c40bcbd6..5d9aa31865 100644
--- a/core/src/chacha_cuda.rs
+++ b/core/src/chacha_cuda.rs
@@ -54,6 +54,9 @@ pub fn chacha_cbc_encrypt_file_many_keys(
                     "chacha_cuda: encrypting segment: {} num_entries: {} entry_len: {}",
                     segment, num_entries, entry_len
                 );
+                if num_entries == 0 {
+                    break;
+                }
                 let entry_len_usz = entry_len as usize;
                 unsafe {
                     chacha_cbc_encrypt_many_sample(