fix(esplora): check recent blocks are not empty

Author: rustaceanrob

crates/esplora/src/async_ext.rs

@@ -188,6 +188,9 @@ async fn fetch_block(
         return Ok(Some(hash));
     }
 
+    if latest_blocks.is_empty() {
+        return Ok(None);
+    }
     // We avoid fetching blocks higher than previously fetched `latest_blocks` as the local chain
     // tip is used to signal for the last-synced-up-to-height.
     let &tip_height = latest_blocks

crates/esplora/src/blocking_ext.rs

@@ -178,6 +178,9 @@ fn fetch_block(
         return Ok(Some(hash));
     }
 
+    if latest_blocks.is_empty() {
+        return Ok(None);
+    }
     // We avoid fetching blocks higher than previously fetched `latest_blocks` as the local chain
     // tip is used to signal for the last-synced-up-to-height.
     let &tip_height = latest_blocks