Merge pull request #1184 from katzyn/constraint

Do not change ID of existing constraints in AlterTableAddConstraint

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

@@ -54,6 +54,11 @@ public abstract class Prepared {
 
     private long modificationMetaId;
     private Command command;
+    /**
+     * Used to preserve object identities on database startup. {@code 0} if
+     * object is not stored, {@code -1} if object is stored and its ID is
+     * already read, {@code >0} if object is stored and its id is not yet read.
+     */
     private int objectId;
     private int currentRowNumber;
     private int rowScanCount;
@@ -245,12 +250,14 @@ public abstract class Prepared {
      * @return the object id or 0 if not set
      */
     protected int getCurrentObjectId() {
-        return objectId;
+        int id = objectId;
+        return id >= 0 ? id : 0;
     }
 
     /**
      * Get the current object id, or get a new id from the database. The object
-     * id is used when creating new database object (CREATE statement).
+     * id is used when creating new database object (CREATE statement). This
+     * method may be called only once.
      *
      * @return the object id
      */
@@ -258,9 +265,10 @@ public abstract class Prepared {
         int id = objectId;
         if (id == 0) {
             id = session.getDatabase().allocateObjectId();
-        } else {
-            objectId = 0;
+        } else if (id < 0) {
+            throw DbException.throwInternalError("Prepared.getObjectId() was called before");
         }
+        objectId = -1;
         return id;
     }
 

h2/src/main/org/h2/command/ddl/AlterTableAddConstraint.java

@@ -137,25 +137,24 @@ public class AlterTableAddConstraint extends SchemaCommand {
                         throw DbException.get(ErrorCode.SECOND_PRIMARY_KEY);
                     }
                 }
-            }
-            if (index == null) {
+            } else {
                 IndexType indexType = IndexType.createPrimaryKey(
                         table.isPersistIndexes(), primaryKeyHash);
                 String indexName = table.getSchema().getUniqueIndexName(
                         session, table, Constants.PREFIX_PRIMARY_KEY);
-                int id = getObjectId();
+                int indexId = session.getDatabase().allocateObjectId();
                 try {
-                    index = table.addIndex(session, indexName, id,
+                    index = table.addIndex(session, indexName, indexId,
                             indexColumns, indexType, true, null);
                 } finally {
                     getSchema().freeUniqueName(indexName);
                 }
             }
             index.getIndexType().setBelongsToConstraint(true);
-            int constraintId = getObjectId();
+            int id = getObjectId();
             String name = generateConstraintName(table);
             ConstraintUnique pk = new ConstraintUnique(getSchema(),
-                    constraintId, name, table, true);
+                    id, name, table, true);
             pk.setColumns(indexColumns);
             pk.setIndex(index, true);
             constraint = pk;
@@ -277,7 +276,7 @@ public class AlterTableAddConstraint extends SchemaCommand {
     }
 
     private Index createIndex(Table t, IndexColumn[] cols, boolean unique) {
-        int indexId = getObjectId();
+        int indexId = session.getDatabase().allocateObjectId();
         IndexType indexType;
         if (unique) {
             // for unique constraints

h2/src/main/org/h2/command/ddl/CommandWithColumns.java

@@ -103,7 +103,7 @@ public abstract class CommandWithColumns extends SchemaCommand {
         if (columns != null) {
             for (Column c : columns) {
                 if (c.isAutoIncrement()) {
-                    int objId = getObjectId();
+                    int objId = session.getDatabase().allocateObjectId();
                     c.convertAutoIncrementToSequence(session, getSchema(), objId, temporary);
                     if (!Constants.CLUSTERING_DISABLED.equals(session.getDatabase().getCluster())) {
                         throw DbException.getUnsupportedException("CLUSTERING && auto-increment columns");