SERVER-40546 max/min boundary checking on both

2 files changed, 18 insertions, 2 deletions

diff --git a/jstests/core/collation.js b/jstests/core/collation.js
index af87212346c..6b13cceadfd 100644
--- a/jstests/core/collation.js
+++ b/jstests/core/collation.js
@@ -1975,6 +1975,20 @@
                                       .itcount());
         assert.commandFailedWithCode(err, 51174);
 
+        // This query should fail, because the hinted index does not match the requested
+        // collation, and the 'max' value is a string, which means we cannot ignore the
+        // collation.
+        const caseInsensitive = {locale: "en", strength: 2};
+        assert.commandWorked(coll.dropIndexes());
+        assert.commandWorked(coll.createIndex({str: 1}));
+        err = assert.throws(() => coll.find({}, {_id: 0})
+                                      .min({str: MinKey})
+                                      .max({str: "Hello1"})
+                                      .hint({str: 1})
+                                      .collation(caseInsensitive)
+                                      .toArray());
+        assert.commandFailedWithCode(err, 51174);
+
         // After building an index with the case-insensitive US English collation, the query should
         // work. Furthermore, the bounds defined by the min and max should respect the
         // case-insensitive collation.
diff --git a/src/mongo/db/query/query_planner.cpp b/src/mongo/db/query/query_planner.cpp
index 655a6816194..9e8349b18d5 100644
--- a/src/mongo/db/query/query_planner.cpp
+++ b/src/mongo/db/query/query_planner.cpp
@@ -657,8 +657,10 @@ StatusWith<std::vector<std::unique_ptr<QuerySolution>>> QueryPlanner::plan(
         BSONObj minObj = query.getQueryRequest().getMin();
         BSONObj maxObj = query.getQueryRequest().getMax();
 
-        if (!indexCompatibleMaxMin(
-                minObj.isEmpty() ? maxObj : minObj, query.getCollator(), *hintedIndexEntry)) {
+        if ((!minObj.isEmpty() &&
+             !indexCompatibleMaxMin(minObj, query.getCollator(), *hintedIndexEntry)) ||
+            (!maxObj.isEmpty() &&
+             !indexCompatibleMaxMin(maxObj, query.getCollator(), *hintedIndexEntry))) {
             return Status(ErrorCodes::Error(51174),
                           "The index chosen is not compatible with min/max");
         }