fixed issue #13632 (#13679)

CHANGELOG

@@ -1,6 +1,8 @@
 v3.7.10 (XXXX-XX-XX)
 --------------------
 
+* Fixed Github issue #13632: Query Fails on Upsert with Replace_nth.
+
 * Backported AQL sort performance improvements from devel.
   This change can improve the performance of local sorts operations, e.g.
 

arangod/Aql/Functions.cpp

@@ -7340,9 +7340,10 @@ AqlValue Functions::ReplaceNth(ExpressionContext* expressionContext,
     THROW_ARANGO_EXCEPTION_PARAMS(TRI_ERROR_QUERY_FUNCTION_ARGUMENT_TYPE_MISMATCH, AFN);
   }
 
-  AqlValueMaterializer materializer(trx);
-  VPackSlice arraySlice = materializer.slice(baseArray, false);
-  VPackSlice replaceValue = materializer.slice(newValue, false);
+  AqlValueMaterializer materializer1(trx);
+  VPackSlice arraySlice = materializer1.slice(baseArray, false);
+  AqlValueMaterializer materializer2(trx);
+  VPackSlice replaceValue = materializer2.slice(newValue, false);
 
   transaction::BuilderLeaser builder(trx);
   builder->openArray();
@@ -7359,6 +7360,7 @@ AqlValue Functions::ReplaceNth(ExpressionContext* expressionContext,
 
   uint64_t pos = length;
   if (replaceOffset >= length) {
+    AqlValueMaterializer materializer(trx);
     VPackSlice paddVpValue = materializer.slice(paddValue, false);
     while (pos < replaceOffset) {
       builder->add(paddVpValue);

tests/js/server/aql/aql-functions.js

@@ -885,7 +885,6 @@ function ahuacatlFunctionsTestSuite () {
 ////////////////////////////////////////////////////////////////////////////////
 
     testReplaceNthCxx : function () {
-
       var testArray = [
         null,
         true,
@@ -939,6 +938,29 @@ function ahuacatlFunctionsTestSuite () {
       }
     },
 
+    testReplaceNthIssue13632 : function () {
+      let query = `
+LET first = NOOPT({v: {t1: []}})
+FOR s IN NOOPT([["t1", 0, 0, null], ["t1", 1, 0, first]])
+  LET t = s[0]
+  LET index = s[1]
+  LET value = s[2]
+  LET old = s[3]
+  RETURN [old, IS_NULL(old) ? first : MERGE(first, {v: {[t]: REPLACE_NTH(old.v[t], index, value, value)}})]
+`;
+      let actual = getQueryResults(query);
+      assertEqual(2, actual.length);
+
+      let OLD, NEW;
+      [OLD, NEW] = actual[0];
+      assertNull(OLD);
+      assertEqual({ t1: [] }, NEW.v);
+
+      [OLD, NEW] = actual[1];
+      assertEqual({ t1: [] }, OLD.v);
+      assertEqual({ t1: [0, 0] }, NEW.v);
+    },
+
 ////////////////////////////////////////////////////////////////////////////////
 /// @brief test replace_nth function
 ////////////////////////////////////////////////////////////////////////////////