updating stubs per filetype: no need to remove the version directory

java/java-tests/testSrc/com/intellij/util/indexing/FileBasedIndexTest.java

@@ -0,0 +1,18 @@
+package com.intellij.util.indexing;
+
+import com.intellij.testFramework.fixtures.LightCodeInsightFixtureTestCase;
+
+/**
+ * @author Dmitry Avdeev
+ *         Date: 5/23/13
+ */
+public class FileBasedIndexTest extends LightCodeInsightFixtureTestCase {
+
+  public void testSurviveOnFileTypeChange() throws Exception {
+    myFixture.configureByText("Foo.java", "class Foo { String bar; }");
+    myFixture.testHighlighting();
+    FileTypeIndexTest.addAndRemoveFileType();
+    myFixture.configureByText("Bar.java", "class Bar { String bar; }");
+    myFixture.testHighlighting();
+  }
+}

platform/lang-impl/src/com/intellij/psi/stubs/StubUpdatingIndex.java

@@ -35,7 +35,6 @@ import org.jetbrains.annotations.NotNull;
 
 import java.io.DataInput;
 import java.io.DataOutput;
-import java.io.File;
 import java.io.IOException;
 import java.util.*;
 import java.util.concurrent.Callable;
@@ -405,8 +404,8 @@ public class StubUpdatingIndex extends CustomImplementationFileBasedIndexExtensi
           }
         }
 
-        File dir= IndexInfrastructure.getStubVersionsDirectory();
-        if (dir.exists()) dir.delete();
+        //File dir= IndexInfrastructure.getStubVersionsDirectory();
+        //if (dir.exists()) dir.delete();
         super.clear();
       }
       finally {

platform/lang-impl/src/com/intellij/util/indexing/IndexInfrastructure.java

@@ -74,10 +74,6 @@ public class IndexInfrastructure {
     return indexDir;
   }
 
-  public static File getStubVersionsDirectory() {
-    return new File(getIndexRootDir(StubUpdatingIndex.INDEX_ID), STUB_VERSIONS);
-  }
-
   private static volatile long ourLastStamp; // ensure any file index stamp increases
 
   public static synchronized void rewriteVersion(final File file, final int version) throws IOException {

platform/platform-tests/testSrc/com/intellij/util/indexing/FileTypeIndexTest.java

@@ -13,13 +13,14 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package com.intellij.psi.search;
+package com.intellij.util.indexing;
 
 import com.intellij.openapi.fileTypes.FileType;
 import com.intellij.openapi.fileTypes.FileTypeManager;
 import com.intellij.openapi.fileTypes.ex.FakeFileType;
 import com.intellij.openapi.fileTypes.ex.FileTypeManagerEx;
 import com.intellij.openapi.vfs.VirtualFile;
+import com.intellij.psi.search.FileTypeIndex;
 import com.intellij.testFramework.PlatformTestCase;
 import com.intellij.testFramework.fixtures.LightPlatformCodeInsightFixtureTestCase;
 import org.jetbrains.annotations.NotNull;
@@ -35,6 +36,10 @@ public class FileTypeIndexTest extends LightPlatformCodeInsightFixtureTestCase {
   }
 
   public void testAddFileType() throws Exception {
+    addAndRemoveFileType();
+  }
+
+  static void addAndRemoveFileType() {
     FileType foo = new FakeFileType() {
       @Override
       public boolean isMyFileType(VirtualFile file) {