Fix Select and grouping bugs

- Deep copy the grouping structure on query copy.
  It is mutable but we have neglected doing this right until now.
- Fix a bug in the previous commit where the last constructed Query.Model was shared between all instances.
- Fix a bug in the previous commit where the query string instead of the query tree was reset when a new select
  expression is set.
- Don't use deprecated method.
- Clean up Javadoc and formatting.

1 files changed, 13 insertions, 4 deletions

diff --git a/container-search/src/main/java/com/yahoo/search/grouping/request/MinFunction.java b/container-search/src/main/java/com/yahoo/search/grouping/request/MinFunction.java
index 478684dd73e..40fbda5a98a 100644
--- a/container-search/src/main/java/com/yahoo/search/grouping/request/MinFunction.java
+++ b/container-search/src/main/java/com/yahoo/search/grouping/request/MinFunction.java
@@ -1,7 +1,9 @@
 // Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.search.grouping.request;
 
+import java.util.Arrays;
 import java.util.List;
+import java.util.stream.Collectors;
 
 /**
  * This class represents a min-function in a {@link GroupingExpression}. It evaluates to a number that equals the
@@ -19,11 +21,18 @@ public class MinFunction extends FunctionNode {
      * @param argN The optional arguments, must evaluate to a number.
      */
     public MinFunction(GroupingExpression arg1, GroupingExpression arg2, GroupingExpression... argN) {
-        this(asList(arg1, arg2, argN));
+        this(null, null, asList(arg1, arg2, argN));
     }
 
-    private MinFunction(List<GroupingExpression> args) {
-        super("min", args);
+    private MinFunction(String label, Integer level, List<GroupingExpression> args) {
+        super("min", label, level, args);
+    }
+
+    @Override
+    public MinFunction copy() {
+        return new MinFunction(getLabel(),
+                               getLevelOrNull(),
+                               args().stream().map(arg -> arg.copy()).collect(Collectors.toList()));
     }
 
     /**
@@ -37,7 +46,7 @@ public class MinFunction extends FunctionNode {
         if (args.size() < 2) {
             throw new IllegalArgumentException("Expected 2 or more arguments, got " + args.size() + ".");
         }
-        return new MinFunction(args);
+        return new MinFunction(null, null, args);
     }
 }