more tests and fixes

h2/src/main/org/h2/command/Parser.java

@@ -4729,8 +4729,14 @@ public class Parser {
                 .substring(parseIndex));
         read("AS");
         try {
-            Query query = parseSelect();
-            query.prepare();
+            Query query;
+            session.setParsingView(true);
+            try {
+                query = parseSelect();
+                query.prepare();
+            } finally {
+                session.setParsingView(false);
+            }
             command.setSelect(query);
         } catch (DbException e) {
             if (force) {

h2/src/main/org/h2/index/ViewIndex.java

@@ -88,7 +88,7 @@ public class ViewIndex extends BaseIndex implements SpatialIndex {
         this.indexMasks = masks;
         this.createSession = session;
         columns = new Column[0];
-        if (!recursive) {
+        if (!recursive && filters != null) {
             query = getQuery(session, masks, filters, filter, sortOrder);
         }
     }
@@ -136,7 +136,7 @@ public class ViewIndex extends BaseIndex implements SpatialIndex {
     @Override
     public synchronized double getCost(Session session, int[] masks,
             TableFilter[] filters, int filter, SortOrder sortOrder) {
-        if (recursive) {
+        if (recursive || filters == null) {
             return 1000;
         }
         IntArray masksArray = new IntArray(masks == null ?
@@ -177,6 +177,10 @@ public class ViewIndex extends BaseIndex implements SpatialIndex {
             String sql = q.getPlanSQL();
             q = prepareSubQuery(sql, session, masks, filters, filter, sortOrder, false);
         }
+        if (query == null) {
+            // this is possible when scan index has been taken and the cost was recalculated
+            query = q;
+        }
         double cost = q.getCost();
         cachedCost = new CostElement();
         cachedCost.evaluatedAt = System.currentTimeMillis();

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

@@ -41,6 +41,7 @@ import org.h2.result.Row;
 import org.h2.result.SearchRow;
 import org.h2.result.SortOrder;
 import org.h2.table.IndexColumn;
+import org.h2.table.SubQueryInfo;
 import org.h2.table.Table;
 import org.h2.table.TableBase;
 import org.h2.table.TableFilter;
@@ -350,11 +351,20 @@ public class TestTableEngines extends TestBase {
         Statement stat = conn.createStatement();
         stat.execute("create table SUB_QUERY_TEST(id int primary key, name varchar) ENGINE \"" +
                 TreeSetIndexTableEngine.class.getName() + "\"");
-        stat.execute("create table t1(id int, birthday date)");
-        stat.executeQuery("select t1.birthday from t1, "
-                + "(select t2.id from sub_query_test t2, "
-                + "(select t3.id from sub_query_test t3 where t3.name = '') t4 "
-                + "where t2.id = t4.id) t5 where t1.id = t5.id");
+        // test sub-queries
+        stat.executeQuery("select * from "
+                + "(select t2.id from "
+                + "(select t3.id from sub_query_test t3 where t3.name = '') t4, "
+                + "sub_query_test t2 "
+                + "where t2.id = t4.id) t5").next();
+        // test view 1
+        stat.execute("create view t4 as (select t3.id from sub_query_test t3 where t3.name = '')");
+        stat.executeQuery("select * from "
+                + "(select t2.id from t4, sub_query_test t2 where t2.id = t4.id) t5").next();
+        // test view 2
+        stat.execute("create view t5 as "
+                + "(select t2.id from t4, sub_query_test t2 where t2.id = t4.id)");
+        stat.executeQuery("select * from t5").next();
         deleteDb("testSubQueryInfo");
     }
 
@@ -477,7 +487,13 @@ public class TestTableEngines extends TestBase {
             }
         }
     }
-    
+
+    private static void assert0(boolean condition, String message) {
+        if (!condition) {
+            throw new AssertionError(message);
+        }
+    }
+
     private static void setBatchSize(ArrayList<TreeSetTable> tables, int... batchSizes) {
         for (int i = 0; i < batchSizes.length; i++) {
             int batchSize = batchSizes[i];
@@ -1219,13 +1235,26 @@ public class TestTableEngines extends TestBase {
             return new IteratorCursor(subSet.iterator());
         }
 
+        private void checkInfo(SubQueryInfo info) {
+            if (info.getUpper() == null) {
+                // check 1st level info
+                assert0(info.getFilters().length == 1, "getFilters().length " + info.getFilters().length);
+                String alias = info.getFilters()[info.getFilter()].getTableAlias();
+                assert0("T5".equals(alias), "alias: " + alias);
+            } else {
+                // check 2nd level info
+                assert0(info.getFilters().length == 2, "getFilters().length " + info.getFilters().length);
+                String alias = info.getFilters()[info.getFilter()].getTableAlias();
+                assert0("T4".equals(alias), "alias: " + alias);
+                checkInfo(info.getUpper());
+            }
+        }
+
         @Override
         public double getCost(Session session, int[] masks,
                 TableFilter[] filters, int filter, SortOrder sortOrder) {
             if (getTable().getName().equals("SUB_QUERY_TEST")) {
-                if (session.getSubQueryInfo() == null) {
-                    throw new IllegalStateException("No qubquery info found.");
-                }
+                checkInfo(session.getSubQueryInfo());
             }
             return getCostRangeIndex(masks, set.size(), filters, filter, sortOrder);
         }