From 1c5be12515f5ddea075214a95be36655da4abed2 Mon Sep 17 00:00:00 2001
From: Heikki Linnakangas <heikki.linnakangas@iki.fi>
Date: Fri, 11 Jun 2021 10:37:25 +0300
Subject: [PATCH] Fix compilation with Rust versions < 1.50

The bool::then function was added in Rust 1.50. I'm still using 1.48 on
my laptop. We haven't decided what Rust version we will require
(https://github.com/zenithdb/zenith/issues/138), and I'll probably need
to upgrade sooner or later, but this will do for now.
---
 pageserver/src/walreceiver.rs | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/pageserver/src/walreceiver.rs b/pageserver/src/walreceiver.rs
index dc0e9e84db..e1c80932a1 100644
--- a/pageserver/src/walreceiver.rs
+++ b/pageserver/src/walreceiver.rs
@@ -245,7 +245,11 @@ fn walreceiver_main(
                     reply_requested,
                 );
 
-                reply_requested.then(|| timeline.get_last_valid_lsn())
+                if reply_requested {
+                    Some(timeline.get_last_valid_lsn())
+                } else {
+                    None
+                }
             }
 
             _ => None,