From f3086433753354e0e09358f0c32cf78a8d9cef72 Mon Sep 17 00:00:00 2001
From: pascal <pascal.seitz@gmail.com>
Date: Sat, 18 Jul 2026 22:42:48 +0200
Subject: [PATCH] improve BufferedUnionScorer::advance

---
 src/query/union/buffered_union.rs | 21 ++++++++++-----------
 1 file changed, 10 insertions(+), 11 deletions(-)

diff --git a/src/query/union/buffered_union.rs b/src/query/union/buffered_union.rs
index 8540b860d..36789ef43 100644
--- a/src/query/union/buffered_union.rs
+++ b/src/query/union/buffered_union.rs
@@ -144,19 +144,18 @@ where
     TScorer: Scorer,
     TScoreCombiner: ScoreCombiner,
 {
-    #[inline]
     fn advance(&mut self) -> DocId {
-        if self.advance_buffered() {
-            return self.doc;
+        // A loop rather than two sequential advance_buffered calls
+        // produces a single inlined copy
+        loop {
+            if self.advance_buffered() {
+                return self.doc;
+            }
+            if !self.refill() {
+                self.doc = TERMINATED;
+                return TERMINATED;
+            }
         }
-        if !self.refill() {
-            self.doc = TERMINATED;
-            return TERMINATED;
-        }
-        if !self.advance_buffered() {
-            return TERMINATED;
-        }
-        self.doc
     }
 
     fn fill_buffer(&mut self, buffer: &mut [DocId; COLLECT_BLOCK_BUFFER_LEN]) -> usize {