There was a memory leak in the trace system. Opening and closing many…

There was a memory leak in the trace system. Opening and closing many connections could run out of memory.

h2/src/main/org/h2/message/TraceSystem.java

@@ -140,7 +140,7 @@ public class TraceSystem implements TraceWriter {
      */
     public synchronized Trace getTrace(String module) {
         if (module.endsWith("]")) {
-            new Trace(writer, module);
+            return new Trace(writer, module);
         }
         if (traces == null) {
             traces = New.hashMap(16);

h2/src/test/org/h2/test/db/TestMemoryUsage.java

@@ -33,6 +33,7 @@ public class TestMemoryUsage extends TestBase {
     }
 
     public void test() throws SQLException {
+        testOpenCloseConnections();
         if (getBaseDir().indexOf(':') >= 0) {
             // can't test in-memory databases
             return;
@@ -50,6 +51,22 @@ public class TestMemoryUsage extends TestBase {
         deleteDb("memoryUsage");
     }
 
+    private void testOpenCloseConnections() throws SQLException {
+        if (!config.big) {
+            return;
+        }
+        deleteDb("memoryUsage");
+        conn = getConnection("memoryUsage");
+        eatMemory(4000);
+        for (int i = 0; i < 40000; i++) {
+            Connection c2 = getConnection("memoryUsage");
+            c2.createStatement();
+            c2.close();
+        }
+        freeMemory();
+        conn.close();
+    }
+
     private void testCreateDropLoop() throws SQLException {
         deleteDb("memoryUsage");
         conn = getConnection("memoryUsage");