Ensure that we do not end up with a nullptr when accidentally averaging over a string field.

2 files changed, 40 insertions, 2 deletions

diff --git a/searchlib/src/tests/aggregator/perdocexpr.cpp b/searchlib/src/tests/aggregator/perdocexpr.cpp
index 66d2e48194d..c3667c36f8e 100644
--- a/searchlib/src/tests/aggregator/perdocexpr.cpp
+++ b/searchlib/src/tests/aggregator/perdocexpr.cpp
@@ -1325,6 +1325,38 @@ TEST("testAggregationResults") {
                           FloatResultNode(15.54));
 }
 
+TEST("test Average over integer") {
+    AggregationResult::Configure conf;
+    AverageAggregationResult avg;
+    avg.setExpression(createScalarInt(I4)).select(conf, conf);
+    avg.aggregate(0, 0);
+    EXPECT_EQUAL(I4, avg.getAverage().getInteger());
+}
+
+TEST("test Average over float") {
+    AggregationResult::Configure conf;
+    AverageAggregationResult avg;
+    avg.setExpression(createScalarFloat(I4)).select(conf, conf);
+    avg.aggregate(0, 0);
+    EXPECT_EQUAL(I4, avg.getAverage().getInteger());
+}
+
+TEST("test Average over numeric string") {
+    AggregationResult::Configure conf;
+    AverageAggregationResult avg;
+    avg.setExpression(createScalarString("7.8")).select(conf, conf);
+    avg.aggregate(0, 0);
+    EXPECT_EQUAL(7.8, avg.getAverage().getFloat());
+}
+
+TEST("test Average over non-numeric string") {
+    AggregationResult::Configure conf;
+    AverageAggregationResult avg;
+    avg.setExpression(createScalarString("ABC")).select(conf, conf);
+    avg.aggregate(0, 0);
+    EXPECT_EQUAL(0, avg.getAverage().getInteger());
+}
+
 TEST("testGrouping") {
     AttributeGuard attr1 = createInt64Attribute();
     ExpressionNode::UP result1(new CountAggregationResult());
diff --git a/searchlib/src/vespa/searchlib/aggregation/aggregation.cpp b/searchlib/src/vespa/searchlib/aggregation/aggregation.cpp
index 0b8ed669874..006d26a53b0 100644
--- a/searchlib/src/vespa/searchlib/aggregation/aggregation.cpp
+++ b/searchlib/src/vespa/searchlib/aggregation/aggregation.cpp
@@ -155,7 +155,13 @@ AverageAggregationResult::onPrepare(const ResultNode & result, bool useForInit)
     if (isReady(_sum.get(), result)) {
         return;
     }
-    _sum.reset(dynamic_cast<NumericResultNode *>(result.createBaseType().release()));
+    
+    ResultNode::UP tmp = result.createBaseType();
+    if (dynamic_cast<NumericResultNode *>(tmp.get())) {
+        _sum.reset(static_cast<NumericResultNode *>(tmp.release()));
+    } else {
+        _sum.reset(new FloatResultNode());
+    }
     if ( useForInit ) {
         _sum->set(result);
     }
@@ -546,7 +552,7 @@ ExpressionCountAggregationResult::ExpressionCountAggregationResult() = default;
 ExpressionCountAggregationResult::~ExpressionCountAggregationResult() = default;
 
 StandardDeviationAggregationResult::StandardDeviationAggregationResult()
-        : AggregationResult(), _count(), _sum(), _sumOfSquared(), _stdDevScratchPad()
+    : AggregationResult(), _count(), _sum(), _sumOfSquared(), _stdDevScratchPad()
 {
     _stdDevScratchPad.reset(new expression::FloatResultNode());
 }