From c46fe90010adaee8a241a2241b417ecff2f037d9 Mon Sep 17 00:00:00 2001
From: Arseny Sher <sher-ars@yandex.ru>
Date: Thu, 5 May 2022 07:43:55 +0400
Subject: [PATCH] Fix division by zero in WAL removal.

---
 safekeeper/src/safekeeper.rs | 4 +---
 safekeeper/src/timeline.rs   | 4 ++++
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/safekeeper/src/safekeeper.rs b/safekeeper/src/safekeeper.rs
index 67d41d0b58..68361fd672 100644
--- a/safekeeper/src/safekeeper.rs
+++ b/safekeeper/src/safekeeper.rs
@@ -938,9 +938,7 @@ where
             ),
             self.state.s3_wal_lsn,
         );
-        let res = horizon_lsn.segment_number(self.state.server.wal_seg_size as usize);
-        info!("horizon is {}, res {}", horizon_lsn, res);
-        res
+        horizon_lsn.segment_number(self.state.server.wal_seg_size as usize)
     }
 }
 
diff --git a/safekeeper/src/timeline.rs b/safekeeper/src/timeline.rs
index 745d8e0893..47137091da 100644
--- a/safekeeper/src/timeline.rs
+++ b/safekeeper/src/timeline.rs
@@ -469,6 +469,10 @@ impl Timeline {
         let remover: Box<dyn Fn(u64) -> Result<(), anyhow::Error>>;
         {
             let shared_state = self.mutex.lock().unwrap();
+            // WAL seg size not initialized yet, no WAL exists.
+            if shared_state.sk.state.server.wal_seg_size == 0 {
+                return Ok(());
+            }
             horizon_segno = shared_state.sk.get_horizon_segno();
             remover = shared_state.sk.wal_store.remove_up_to();
             if horizon_segno <= 1 || horizon_segno <= shared_state.last_removed_segno {