Do not allocate a new ValueArray in convertPrecision if not required

h2/src/main/org/h2/value/ValueArray.java

@@ -7,13 +7,12 @@ package org.h2.value;
 
 import java.lang.reflect.Array;
 import java.sql.PreparedStatement;
-import java.util.ArrayList;
+import java.util.Arrays;
 
 import org.h2.engine.Constants;
 import org.h2.engine.SysProperties;
 import org.h2.util.MathUtils;
 import org.h2.util.StatementBuilder;
-import org.h2.util.Utils;
 
 /**
  * Implementation of the ARRAY data type.
@@ -207,18 +206,28 @@ public class ValueArray extends Value {
         if (!force) {
             return this;
         }
-        ArrayList<Value> list = Utils.newSmallArrayList();
-        for (Value v : values) {
-            v = v.convertPrecision(precision, true);
+        int length = values.length;
+        Value[] newValues = new Value[length];
+        int i = 0;
+        boolean modified = false;
+        for (; i < length; i++) {
+            Value old = values[i];
+            Value v = old.convertPrecision(precision, true);
+            if (v != old) {
+                modified = true;
+            }
             // empty byte arrays or strings have precision 0
             // they count as precision 1 here
             precision -= Math.max(1, v.getPrecision());
             if (precision < 0) {
                 break;
             }
-            list.add(v);
+            newValues[i] = v;
+        }
+        if (i < length) {
+            return get(Arrays.copyOf(newValues, i));
         }
-        return get(list.toArray(new Value[0]));
+        return modified ? get(newValues) : this;
     }
 
 }

h2/src/test/org/h2/test/unit/TestValue.java

@@ -336,7 +336,7 @@ public class TestValue extends TestBase {
                 new Value[] {ValueString.get("1"), ValueString.get("22"), ValueString.get("333")});
         assertEquals(6, src.getPrecision());
         assertSame(src, src.convertPrecision(5, false));
-        assertEquals(src, src.convertPrecision(6, true));
+        assertSame(src, src.convertPrecision(6, true));
         ValueArray exp = ValueArray.get(
                 new Value[] {ValueString.get("1"), ValueString.get("22"), ValueString.get("33")});
         assertEquals(exp, src.convertPrecision(5, true));