arangodb · jsteemann · Sep 10, 2018 · Sep 8, 2018 · Sep 10, 2018 · Sep 10, 2018
diff --git a/arangod/Aql/Aggregator.cpp b/arangod/Aql/Aggregator.cpp
@@ -226,14 +226,16 @@ struct AggregatorMax final : public Aggregator {
 
 struct AggregatorSum final : public Aggregator {
   explicit AggregatorSum(transaction::Methods* trx)
-      : Aggregator(trx), sum(0.0), invalid(false) {}
+      : Aggregator(trx), sum(0.0), invalid(false), invoked(false) {}
 
   void reset() override {
     sum = 0.0;
     invalid = false;
+    invoked = false;
   }
 
   void reduce(AqlValue const& cmpValue) override {
+    invoked = true;
     if (!invalid) {
       if (cmpValue.isNull(true)) {
         // ignore `null` values here
@@ -253,7 +255,7 @@ struct AggregatorSum final : public Aggregator {
   }
 
   AqlValue stealValue() override {
-    if (invalid || std::isnan(sum) || sum == HUGE_VAL || sum == -HUGE_VAL) {
+    if (invalid || !invoked || std::isnan(sum) || sum == HUGE_VAL || sum == -HUGE_VAL) {
       return AqlValue(AqlValueHintNull());
     }
 
@@ -266,6 +268,7 @@ struct AggregatorSum final : public Aggregator {
 
   double sum;
   bool invalid;
+  bool invoked;
 };
 
 /// @brief the single-server variant of AVERAGE

diff --git a/arangod/Aql/CollectBlock.cpp b/arangod/Aql/CollectBlock.cpp
@@ -511,11 +511,8 @@ void SortedCollectBlock::emitGroup(AqlItemBlock const* cur, AqlItemBlock* res,
              ++r) {
           it->reduce(getValueForRegister(cur, r, reg));
         }
-        res->setValue(row, _aggregateRegisters[j].first, it->stealValue());
-      } else {
-        res->emplaceValue(row, _aggregateRegisters[j].first,
-                          AqlValueHintNull());
       }
+      res->setValue(row, _aggregateRegisters[j].first, it->stealValue());
       ++j;
     }
 

diff --git a/arangod/Aql/OptimizerRules.cpp b/arangod/Aql/OptimizerRules.cpp
@@ -2128,10 +2128,10 @@ struct SortToIndexNode final : public WalkerWorker<ExecutionNode> {
 
         IndexIteratorOptions opts;
         opts.ascending = sortCondition.isAscending();
-        std::unique_ptr<ExecutionNode> newNode(new IndexNode(
+        auto newNode = std::make_unique<IndexNode>(
             _plan, _plan->nextId(),
             enumerateCollectionNode->collection(), outVariable, usedIndexes,
-            std::move(condition), opts));
+            std::move(condition), opts);
 
         auto n = newNode.release();
 
@@ -2142,6 +2142,7 @@ struct SortToIndexNode final : public WalkerWorker<Exec
8000
utionNode> {
         if (coveredAttributes == sortCondition.numAttributes()) {
           // if the index covers the complete sort condition, we can also remove
           // the sort node
+          n->needsGatherNodeSort(true);
           _plan->unlinkNode(_plan->getNodeById(_sortNode->id()));
         }
       }

diff --git a/js/common/modules/@arangodb/aql/explainer.js b/js/common/modules/@arangodb/aql/explainer.js
@@ -332,7 +332,7 @@ function printIndexes (indexes) {
       var ranges;
       if (indexes[i].hasOwnProperty('condition')) {
         ranges = indexes[i].condition;
-      } else {
+      } else { 
         ranges = '[ ' + indexes[i].ranges + ' ]';
       }
 
@@ -982,11 +982,11 @@ function processQuery (query, explain) {
     if (node.hasOwnProperty('condition') && node.condition.type && node.condition.type === 'n-ary or') {
       idx.condition = buildExpression(node.condition.subNodes[i]);
     } else {
-      if (variable !== false) {
+      if (variable !== false && variable !== undefined) {
         idx.condition = variable;
       }
     }
-    if (idx.condition === '') {
+    if (idx.condition === '' || idx.condition === undefined) {
       idx.condition = '*'; // empty condition. this is likely an index used for sorting or scanning only
     }
     indexes.push(idx);