Index: java/testing/org/apache/derbyTesting/functionTests/tests/lang/userDefMethods.java
===================================================================
--- java/testing/org/apache/derbyTesting/functionTests/tests/lang/userDefMethods.java	(revision 226401)
+++ java/testing/org/apache/derbyTesting/functionTests/tests/lang/userDefMethods.java	(working copy)
@@ -76,5 +76,82 @@
 		pstmt.close();
 	}
 
+	/* ****
+	 * Derby-388: When a set of inserts & updates is performed on a table
+	 * and each update fires a trigger that in turn performs other updates,
+	 * Derby will sometimes try to recompile the trigger in the middle
+	 * of the update process and will throw an NPE when doing so.
+	 */
+	public static void derby388() throws SQLException
+	{
+		System.out.println("Running DERBY-388 Test.");
+		Connection conn = DriverManager.getConnection("jdbc:default:connection");
+		boolean needCommit = !conn.getAutoCommit();
+		Statement s = conn.createStatement();
 
+		// Create our objects.
+		s.execute("CREATE TABLE D388_T1 (ID INT)");
+		s.execute("CREATE TABLE D388_T2 (ID_2 INT)");
+		s.execute(
+			"CREATE TRIGGER D388_TRIG1 AFTER UPDATE OF ID ON D388_T1" +
+			"	REFERENCING NEW AS N_ROW FOR EACH ROW MODE DB2SQL" +
+			"	UPDATE D388_T2" +
+			"	SET ID_2 = " +
+			"	  CASE WHEN (N_ROW.ID <= 0) THEN N_ROW.ID" +
+			"	  ELSE 6 END " +
+			"   WHERE N_ROW.ID < ID_2"
+		);
+
+		if (needCommit)
+			conn.commit();
+
+		// Statement to insert into D388_T1.
+		PreparedStatement ps1 = conn.prepareStatement(
+			"INSERT INTO D388_T1 VALUES (?)");
+
+		// Statement to insert into D388_T2.
+		PreparedStatement ps2 = conn.prepareStatement(
+			"INSERT INTO D388_T2(ID_2) VALUES (?)");
+
+		// Statement that will cause the trigger to fire.
+		Statement st = conn.createStatement();
+		for (int i = 0; i < 20; i++) {
+
+			for (int id = 0; id < 10; id++) {
+
+				ps2.setInt(1, id);
+				ps2.executeUpdate();
+				ps1.setInt(1, 2*id);
+				ps1.executeUpdate();
+
+				if (needCommit)
+					conn.commit();
+
+			}
+
+			// Execute an update, which will fire the trigger.
+			// Note that having the update here is important
+			// for the reproduction.  If we try to remove the
+			// outer loop and just insert lots of rows followed
+			// by a single UPDATE, the problem won't reproduce.
+			st.execute("UPDATE D388_T1 SET ID=5");
+			if (needCommit)
+				conn.commit();
+				
+		}
+
+		// Clean up.
+		s.execute("DROP TABLE D388_T1");
+		s.execute("DROP TABLE D388_T2");
+
+		if (needCommit)
+			conn.commit();
+				
+		st.close();
+		ps1.close();
+		ps2.close();
+
+		System.out.println("DERBY-388 Test Passed.");
+	}
+
 }
Index: java/testing/org/apache/derbyTesting/functionTests/tests/lang/triggerGeneral.sql
===================================================================
--- java/testing/org/apache/derbyTesting/functionTests/tests/lang/triggerGeneral.sql	(revision 226401)
+++ java/testing/org/apache/derbyTesting/functionTests/tests/lang/triggerGeneral.sql	(working copy)
@@ -579,3 +579,15 @@
 delete from x;
 
 drop table x;
+
+-- Derby-388: When a set of inserts/updates is performed on a table
+-- and each update fires a trigger that in turn performs other updates,
+-- Derby will sometimes try to recompile the trigger in the middle
+-- of the update process and will throw an NPE when doing so.
+
+create procedure d388 () language java parameter style java modifies sql data
+	external name 'org.apache.derbyTesting.functionTests.tests.lang.userDefMethods.derby388';
+
+-- Just call the procedure; it will do the rest.
+call d388();
+
Index: java/testing/org/apache/derbyTesting/functionTests/master/triggerGeneral.out
===================================================================
--- java/testing/org/apache/derbyTesting/functionTests/master/triggerGeneral.out	(revision 226401)
+++ java/testing/org/apache/derbyTesting/functionTests/master/triggerGeneral.out	(working copy)
@@ -1227,4 +1227,16 @@
 1 row inserted/updated/deleted
 ij> drop table x;
 0 rows inserted/updated/deleted
+ij> -- Derby-388: When a set of inserts/updates is performed on a table
+-- and each update fires a trigger that in turn performs other updates,
+-- Derby will sometimes try to recompile the trigger in the middle
+-- of the update process and will throw an NPE when doing so.
+create procedure d388 () language java parameter style java modifies sql data
+	external name 'org.apache.derbyTesting.functionTests.tests.lang.userDefMethods.derby388';
+0 rows inserted/updated/deleted
+ij> -- Just call the procedure; it will do the rest.
+call d388();
+Running DERBY-388 Test.
+DERBY-388 Test Passed.
+0 rows inserted/updated/deleted
 ij>