Page store: bugfix and more internal checks

h2/src/main/org/h2/store/PageFreeList.java

@@ -122,8 +122,11 @@ public class PageFreeList extends Page {
     int allocate(int pageId) throws SQLException {
         int idx = pageId - getPos();
         if (idx >= 0 && !used.get(idx)) {
-            store.logUndo(this, data);
+            // set the bit first, because logUndo can
+            // allocate other pages, and we must not
+            // return the same page twice
             used.set(idx);
+            store.logUndo(this, data);
             store.update(this);
         }
         return pageId;

h2/src/main/org/h2/store/PageStore.java

@@ -1018,8 +1018,9 @@ public class PageStore implements CacheWriter {
         }
         for (Index openIndex : metaObjects.values()) {
             if (openIndex.getTable().isTemporary()) {
+                openIndex.truncate(systemSession);
                 openIndex.remove(systemSession);
-                this.removeMetaIndex(openIndex, systemSession);
+                removeMetaIndex(openIndex, systemSession);
             }
             openIndex.close(systemSession);
         }
@@ -1356,7 +1357,11 @@ public class PageStore implements CacheWriter {
     }
 
     private void removeMetaIndex(Index index, Session session) throws SQLException {
-        Row row = metaIndex.getRow(session, index.getId() + 1);
+        int key = index.getId() + 1;
+        Row row = metaIndex.getRow(session, key);
+        if (row.getKey() != key) {
+            Message.throwInternalError();
+        }
         metaIndex.remove(session, row);
     }