In some cases, creating a new table or altering an existing table threw the…

In some cases, creating a new table or altering an existing table threw the exception: Unique index or primary key violation: "PRIMARY KEY ON """".PAGE_INDEX".

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

@@ -607,6 +607,16 @@ public class Database implements DataHandler {
                 setting.setIntValue(Constants.BUILD_ID);
                 addDatabaseObject(systemSession, setting);
             }
+            // mark all ids used in the page store
+            if (pageStore != null) {
+                BitField f = pageStore.getObjectIds();
+                for (int i = 0, len = f.length(); i < len; i++) {
+                    if (f.get(i) && !objectIds.get(i)) {
+                        trace.info("unused object id: " + i);
+                        objectIds.set(i);
+                    }
+                }
+            }
         }
         systemSession.commit(true);
         trace.info("opened {0}", databaseName);

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

@@ -1874,4 +1874,17 @@ public class PageStore implements CacheWriter {
         this.lockFile = lockFile;
     }
 
+    public BitField getObjectIds() {
+        BitField f = new BitField();
+        Cursor cursor = metaIndex.find(systemSession, null, null);
+        while (cursor.next()) {
+            Row row = cursor.get();
+            int id = row.getValue(0).getInt();
+            if (id > 0) {
+                f.set(id);
+            }
+        }
+        return f;
+    }
+
 }