If there is a single child in the ws, that also is a leaf, it will be be lifted out directly.

3 files changed, 19 insertions, 5 deletions

diff --git a/searchlib/src/tests/queryeval/weighted_set_term/weighted_set_term_test.cpp b/searchlib/src/tests/queryeval/weighted_set_term/weighted_set_term_test.cpp
index ec610d20928..bcde2f22a07 100644
--- a/searchlib/src/tests/queryeval/weighted_set_term/weighted_set_term_test.cpp
+++ b/searchlib/src/tests/queryeval/weighted_set_term/weighted_set_term_test.cpp
@@ -167,7 +167,7 @@ void run_simple(bool field_is_filter, bool term_is_not_needed, bool singleTerm)
     }
     WS ws;
     if (singleTerm) {
-        ws.add("3", 30).add("100", 1000);
+        ws.add("3", 30);
     } else {
         ws.add("7", 70).add("5", 50).add("3", 30).add("100", 1000);
     }
@@ -197,6 +197,10 @@ TEST("testSimple unranked") {
     TEST_DO(run_simple(false, true, false));
 }
 
+TEST("testSimple unranked filter filed") {
+    TEST_DO(run_simple(true, true, false));
+}
+
 TEST("testSimple single") {
     TEST_DO(run_simple(false, false, true));
 }
@@ -209,6 +213,10 @@ TEST("testSimple single unranked") {
     TEST_DO(run_simple(false, true, true));
 }
 
+TEST("testSimple single unranked filter field") {
+    TEST_DO(run_simple(true, true, true));
+}
+
 void run_multi(bool field_is_filter, bool term_is_not_needed)
 {
     FakeSearchable index;
diff --git a/searchlib/src/vespa/searchlib/queryeval/blueprint.h b/searchlib/src/vespa/searchlib/queryeval/blueprint.h
index 882db00c059..3dd20d73373 100644
--- a/searchlib/src/vespa/searchlib/queryeval/blueprint.h
+++ b/searchlib/src/vespa/searchlib/queryeval/blueprint.h
@@ -26,6 +26,7 @@ namespace search::queryeval {
 class SearchIterator;
 class ExecuteInfo;
 class MatchingElementsSearch;
+class LeafBlueprint;
 
 /**
  * A Blueprint is an intermediate representation of a search. More
@@ -251,7 +252,7 @@ public:
     virtual bool isEquiv() const { return false; }
     virtual bool isWhiteList() const { return false; }
     virtual bool isIntermediate() const { return false; }
-    virtual bool isLeaf() const { return false; }
+    virtual LeafBlueprint * asLeaf() noexcept { return nullptr; }
     virtual bool isAnd() const { return false; }
     virtual bool isAndNot() const { return false; }
     virtual bool isOr() const { return false; }
@@ -397,7 +398,7 @@ public:
     void fetchPostings(const ExecuteInfo &execInfo) override;
     void freeze() final;
     SearchIteratorUP createSearch(fef::MatchData &md, bool strict) const override;
-    bool isLeaf() const final { return true; }
+    LeafBlueprint * asLeaf() noexcept final { return this; }
 
     virtual bool getRange(vespalib::string & from, vespalib::string & to) const;
     virtual SearchIteratorUP createLeafSearch(const fef::TermFieldMatchDataArray &tfmda, bool strict) const = 0;
diff --git a/searchlib/src/vespa/searchlib/queryeval/weighted_set_term_blueprint.cpp b/searchlib/src/vespa/searchlib/queryeval/weighted_set_term_blueprint.cpp
index f09ad4103d8..d7b98f6b006 100644
--- a/searchlib/src/vespa/searchlib/queryeval/weighted_set_term_blueprint.cpp
+++ b/searchlib/src/vespa/searchlib/queryeval/weighted_set_term_blueprint.cpp
@@ -96,8 +96,13 @@ SearchIterator::UP
 WeightedSetTermBlueprint::createLeafSearch(const fef::TermFieldMatchDataArray &tfmda, bool) const
 {
     assert(tfmda.size() == 1);
-    if ((_terms.size() == 1) && tfmda[0]->isNotNeeded() && _terms[0]->isLeaf()) {
-        return static_cast<LeafBlueprint &>(*_terms[0]).createLeafSearch(tfmda, true);
+    if ((_terms.size() == 1) && tfmda[0]->isNotNeeded()) {
+        LeafBlueprint * leaf = _terms[0]->asLeaf();
+        if (leaf != nullptr) {
+            // Always returnin a strict iterator independently of what was required,
+            // as that is what we do with all the children when there are more.
+            return leaf->createLeafSearch(tfmda, true);
+        }
     }
     fef::MatchData::UP md = _layout.createMatchData();
     std::vector<SearchIterator*> children;