The PUBLIC schema could be renamed, which could result in a database that can't…

The PUBLIC schema could be renamed, which could result in a database that can't be opened normally. Now it can no longer be renamed. The schema INFORMATION_SCHEMA can also no longer be renamed.

h2/src/main/org/h2/command/ddl/AlterSchemaRename.java

@@ -40,6 +40,9 @@ public class AlterSchemaRename extends DefineCommand {
     public int update() {
         session.commit(true);
         Database db = session.getDatabase();
+        if (!oldSchema.canDrop()) {
+            throw DbException.get(ErrorCode.SCHEMA_CAN_NOT_BE_DROPPED_1, oldSchema.getName());
+        }
         if (db.findSchema(newSchemaName) != null || newSchemaName.equals(oldSchema.getName())) {
             throw DbException.get(ErrorCode.SCHEMA_ALREADY_EXISTS_1, newSchemaName);
         }

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

@@ -35,6 +35,7 @@ public class TestAlterSchemaRename extends TestBase {
         deleteDb("alter");
         conn = getConnection("alter");
         stat = conn.createStatement();
+        testTryToRenameSystemSchemas();
         testSimpleRename();
         testRenameToExistingSchema();
         testCrossSchemaViews();
@@ -43,6 +44,21 @@ public class TestAlterSchemaRename extends TestBase {
         deleteDb("alter");
     }
 
+    private void testTryToRenameSystemSchemas() throws SQLException {
+        try {
+            stat.execute("alter schema information_schema rename to test_info");
+            fail();
+        } catch (SQLException e) {
+            assertEquals(ErrorCode.SCHEMA_CAN_NOT_BE_DROPPED_1, e.getErrorCode());
+        }
+        stat.execute("create sequence test_sequence");
+        try {
+            stat.execute("alter schema public rename to test_schema");
+            fail();
+        } catch (SQLException e) {
+            assertEquals(ErrorCode.SCHEMA_CAN_NOT_BE_DROPPED_1, e.getErrorCode());
+        }
+    }
 
     private void testSimpleRename() throws SQLException {
         stat.execute("create schema s1");