From 6fe9d06f659c1952b7d31d1d7ed0df2533e034b3 Mon Sep 17 00:00:00 2001
From: discord9 <55937128+discord9@users.noreply.github.com>
Date: Sun, 25 Oct 2026 21:25:23 +0800
Subject: [PATCH] fix(promql): preserve partial prefix rejection diagnostic

Signed-off-by: discord9 <55937128+discord9@users.noreply.github.com>
---
 src/promql/src/extension_plan/fused_series.rs | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/promql/src/extension_plan/fused_series.rs b/src/promql/src/extension_plan/fused_series.rs
index 59bd940dd15..2124a21909c 100644
--- a/src/promql/src/extension_plan/fused_series.rs
+++ b/src/promql/src/extension_plan/fused_series.rs
@@ -221,9 +221,14 @@ impl FusedSeries {
         op: BoundAggregate,
     ) -> DataFusionResult<Self> {
         validate_binding(&tree, &binding, children.len())?;
-        if children.len() != 1 || reads_across_series(tree.root()) {
+        if children.len() != 1 {
             return Err(DataFusionError::Plan(
-                "FusedSeries partial fold requires one raw child and a per-partition prefix".into(),
+                "FusedSeries partial fold requires one raw child".into(),
+            ));
+        }
+        if reads_across_series(tree.root()) {
+            return Err(DataFusionError::Plan(
+                "FusedSeries partial fold prefix reads across series".into(),
             ));
         }
         aggregate_op(&op)?;