encapsulate TransactionStore.store field in preparation to a move into a…

encapsulate TransactionStore.store field in preparation to a move into a separate package  and susequent split

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

@@ -515,7 +515,7 @@ public class MVTable extends TableBase {
         int mainIndexColumn;
         mainIndexColumn = getMainIndexColumn(indexType, cols);
         if (database.isStarting()) {
-            if (transactionStore.store.hasMap("index." + indexId)) {
+            if (transactionStore.hasMap("index." + indexId)) {
                 mainIndexColumn = -1;
             }
         } else if (primaryIndex.getRowCountMax() != 0) {

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

@@ -266,17 +266,11 @@ public class MVTableEngine implements TableEngine {
         public void removeTemporaryMaps(BitSet objectIds) {
             for (String mapName : store.getMapNames()) {
                 if (mapName.startsWith("temp.")) {
-                    MVMap<?, ?> map = store.openMap(mapName);
-                    store.removeMap(map);
+                    store.removeMap(mapName);
                 } else if (mapName.startsWith("table.") || mapName.startsWith("index.")) {
                     int id = Integer.parseInt(mapName.substring(1 + mapName.indexOf('.')));
                     if (!objectIds.get(id)) {
-                        ValueDataType keyType = new ValueDataType(null, null, null);
-                        ValueDataType valueType = new ValueDataType(null, null, null);
-                        Transaction t = transactionStore.begin();
-                        TransactionMap<?, ?> m = t.openMap(mapName, keyType, valueType);
-                        transactionStore.removeMap(m);
-                        t.commit();
+                        store.removeMap(mapName);
                     }
                 }
             }

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

@@ -148,6 +148,16 @@ public class TransactionStore {
         this.maxTransactionId = max;
     }
 
+    /**
+     * Check whether a given map exists.
+     *
+     * @param name the map name
+     * @return true if it exists
+     */
+    public boolean hasMap(String name) {
+        return store.hasMap(name);
+    }
+
     /**
      * Combine the transaction id and the log id to an operation id.
      *