From ae4a237e580a38b930c8422297b275cb08819aac Mon Sep 17 00:00:00 2001
From: Kerollmops <clement@meilisearch.com>
Date: Wed, 24 Feb 2021 15:36:57 +0100
Subject: [PATCH] Fix the maximum_proximity function

---
 milli/src/search/criteria/mod.rs | 8 +++++++-
 milli/src/search/query_tree.rs   | 5 ++++-
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/milli/src/search/criteria/mod.rs b/milli/src/search/criteria/mod.rs
index 41cd6722c..52367ac5f 100644
--- a/milli/src/search/criteria/mod.rs
+++ b/milli/src/search/criteria/mod.rs
@@ -153,8 +153,14 @@ fn query_docids(ctx: &dyn Context, query: &Query) -> anyhow::Result<RoaringBitma
 }
 
 fn query_pair_proximity_docids(ctx: &dyn Context, left: &Query, right: &Query, proximity: u8) -> anyhow::Result<RoaringBitmap> {
-    let prefix = right.prefix;
+    if proximity >= 8 {
+        let mut candidates = query_docids(ctx, left)?;
+        let right_candidates = query_docids(ctx, right)?;
+        candidates.intersect_with(&right_candidates);
+        return Ok(candidates);
+    }
 
+    let prefix = right.prefix;
     match (&left.kind, &right.kind) {
         (QueryKind::Exact { word: left, .. }, QueryKind::Exact { word: right, .. }) => {
             if prefix && ctx.in_prefix_cache(&right) {
diff --git a/milli/src/search/query_tree.rs b/milli/src/search/query_tree.rs
index 59f7802f3..47057ad10 100644
--- a/milli/src/search/query_tree.rs
+++ b/milli/src/search/query_tree.rs
@@ -546,7 +546,10 @@ pub fn maximum_proximity(operation: &Operation) -> usize {
     use Operation::{Or, And, Query, Consecutive};
     match operation {
         Or(_, ops) => ops.iter().map(maximum_proximity).max().unwrap_or(0),
-        And(ops) => ops.len().saturating_sub(1) * 8,
+        And(ops) => {
+            ops.iter().map(maximum_proximity).sum::<usize>()
+            + ops.len().saturating_sub(1) * 7
+        },
         Query(_) | Consecutive(_) => 0,
     }
 }