handle (ignore) R/O case

h2/src/main/org/h2/engine/Database.java

@@ -845,12 +845,9 @@ public class Database implements DataHandler {
     }
 
     private void handleUpgradeIssues() {
-        if (mvStore != null) {
+        if (mvStore != null && !isReadOnly()) {
             MVStore store = mvStore.getStore();
             if (store.hasMap("index.0")) {
-                if (isReadOnly()) {
-                    throw DbException.get(ErrorCode.GENERAL_ERROR_1, "Upgrade can not be performed while database is in R/O mode");
-                }
                 Index scanIndex = meta.getScanIndex(systemSession);
                 Cursor curs = scanIndex.find(systemSession, null, null);
                 List<Row> allMetaRows = new ArrayList<>();

h2/src/main/org/h2/mvstore/db/MVTable.java

@@ -507,7 +507,7 @@ public class MVTable extends TableBase {
                 ? SearchRow.ROWID_INDEX : getMainIndexColumn(indexType, cols);
         if (database.isStarting()) {
             // if this is not "SYS_ID" table and index does exists as a separate map
-            if (transactionStore.hasMap("index." + indexId)) {
+            if (indexId != 0 && transactionStore.hasMap("index." + indexId)) {
                 // we can not reuse primary index
                 mainIndexColumn = SearchRow.ROWID_INDEX;
             }