Use TreeSet in IndexCondition and remove IndexCursor.inResultTested

h2/src/main/org/h2/command/dml/Query.java

@@ -319,6 +319,15 @@ public abstract class Query extends Prepared {
         return distinct;
     }
 
+    /**
+     * Returns whether results support random access.
+     *
+     * @return whether results support random access
+     */
+    public boolean isRandomAccessResult() {
+        return randomAccessResult;
+    }
+
     /**
      * Whether results need to support random access.
      *

h2/src/main/org/h2/index/IndexCondition.java

@@ -7,8 +7,8 @@ package org.h2.index;
 
 import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.HashSet;
 import java.util.List;
+import java.util.TreeSet;
 import org.h2.command.dml.Query;
 import org.h2.engine.Session;
 import org.h2.expression.Expression;
@@ -123,8 +123,8 @@ public class IndexCondition {
      * @return the index condition
      */
     public static IndexCondition getInQuery(ExpressionColumn column, Query query) {
-        IndexCondition cond = new IndexCondition(Comparison.IN_QUERY, column,
-                null);
+        assert query.isRandomAccessResult();
+        IndexCondition cond = new IndexCondition(Comparison.IN_QUERY, column, null);
         cond.expressionQuery = query;
         return cond;
     }
@@ -147,7 +147,7 @@ public class IndexCondition {
      * @return the value list
      */
     public Value[] getCurrentValueList(Session session) {
-        HashSet<Value> valueSet = new HashSet<>();
+        TreeSet<Value> valueSet = new TreeSet<>(session.getDatabase().getCompareMode());
         for (Expression e : expressionList) {
             Value v = e.getValue(session);
             v = column.convert(v);

h2/src/main/org/h2/index/IndexCursor.java

@@ -6,7 +6,6 @@
 package org.h2.index;
 
 import java.util.ArrayList;
-import java.util.HashSet;
 
 import org.h2.engine.Session;
 import org.h2.expression.condition.Comparison;
@@ -45,7 +44,6 @@ public class IndexCursor implements Cursor {
     private int inListIndex;
     private Value[] inList;
     private ResultInterface inResult;
-    private HashSet<Value> inResultTested;
 
     public IndexCursor(TableFilter filter) {
         this.tableFilter = filter;
@@ -79,7 +77,6 @@ public class IndexCursor implements Cursor {
         inList = null;
         inColumn = null;
         inResult = null;
-        inResultTested = null;
         intersects = null;
         for (IndexCondition condition : indexConditions) {
             if (condition.isAlwaysFalse()) {
@@ -311,17 +308,12 @@ public class IndexCursor implements Cursor {
             while (inResult.next()) {
                 Value v = inResult.currentRow()[0];
                 if (v != ValueNull.INSTANCE) {
-                    if (inResultTested == null) {
-                        inResultTested = new HashSet<>();
-                    }
-                    if (inResultTested.add(v)) {
                     find(v);
                     break;
                 }
             }
         }
     }
-    }
 
     private void find(Value v) {
         v = inColumn.convert(v);

h2/src/test/org/h2/test/scripts/datatypes/decimal.sql

@@ -29,3 +29,32 @@ SELECT DISTINCT * FROM TEST;
 
 DROP TABLE TEST;
 > ok
+
+CREATE TABLE TEST (N NUMERIC) AS VALUES (0), (0.0), (2), (NULL);
+> ok
+
+CREATE INDEX TEST_IDX ON TEST(N);
+> ok
+
+SELECT N FROM TEST WHERE N IN (0.000, 0.00, 1.0);
+> N
+> ---
+> 0
+> 0.0
+> rows: 2
+
+SELECT N FROM TEST WHERE N IN (SELECT DISTINCT ON(B) A FROM VALUES (0.000, 1), (0.00, 2), (1.0, 3) T(A, B));
+> N
+> ---
+> 0
+> 0.0
+> rows: 2
+
+DROP INDEX TEST_IDX;
+> ok
+
+CREATE UNIQUE INDEX TEST_IDX ON TEST(N);
+> exception DUPLICATE_KEY_1
+
+DROP TABLE TEST;
+> ok