Corrected extensions unregistration.

extensions/source/com/intellij/openapi/extensions/impl/ExtensionPointImpl.java

@@ -276,6 +276,18 @@ public class ExtensionPointImpl implements ExtensionPoint {
     myExtensionAdapters.add(adapter);
   }
 
+  public boolean unregisterComponentAdapter(final ExtensionComponentAdapter componentAdapter) {
+    if (myExtensionAdapters.contains(componentAdapter)) {
+      myExtensionAdapters.remove(componentAdapter);
+      return true;
+    }
+    else if (myLoadedAdapters.contains(componentAdapter)) {
+      unregisterExtension(componentAdapter.getExtension());
+      return true;
+    }
+    return false;
+  }
+
   private static class ObjectComponentAdapter extends ExtensionComponentAdapter {
     private Object myExtension;
     private LoadingOrder myLoadingOrder;

extensions/source/com/intellij/openapi/extensions/impl/ExtensionsAreaImpl.java

@@ -189,8 +189,7 @@ public class ExtensionsAreaImpl implements ExtensionsArea {
     }
     ExtensionComponentAdapter adapter = (ExtensionComponentAdapter) myExtensionElement2extension.remove(extensionElement);
     if (adapter == null) return;
-    if (getExtensionPoint(epName).hasExtension(adapter.getExtension())) {
-      getExtensionPoint(epName).unregisterExtension(adapter.getExtension());
+    if (getExtensionPointImpl(epName).unregisterComponentAdapter(adapter)) {
       MutablePicoContainer pluginContainer = internalGetPluginContainer(pluginName);
       pluginContainer.unregisterComponent(adapter.getComponentKey());
       if (pluginContainer.getComponentAdapters().size() == 0) {

extensions/testSource/com/intellij/openapi/extensions/impl/ExtensionsAreaTest.java

@@ -1,13 +1,13 @@
 package com.intellij.openapi.extensions.impl;
 
+import com.intellij.openapi.extensions.Extensions;
 import junit.framework.TestCase;
-import org.picocontainer.defaults.DefaultPicoContainer;
 import org.picocontainer.MutablePicoContainer;
+import org.picocontainer.defaults.DefaultPicoContainer;
+import org.jdom.Element;
 
 import java.util.List;
 
-import com.intellij.openapi.extensions.Extensions;
-
 /**
  * @author mike
  */
@@ -28,4 +28,22 @@ public class ExtensionsAreaTest extends TestCase {
     final List adapters = myPicoContainer.getComponentAdaptersOfType(ExtensionsAreaTest.class);
     assertEquals(1, adapters.size());
   }
+
+  public void testNoCreateOnUnregisterElement() {
+    myExtensionsArea.registerExtensionPoint("test.ep", TestClass.class.getName());
+    final Element element = ExtensionComponentAdapterTest.readElement("<extension point=\"test.ep\"/>");
+    TestClass.ourCreationCount = 0;
+    myExtensionsArea.registerExtension("test", element);
+    assertEquals(0, TestClass.ourCreationCount);
+    myExtensionsArea.unregisterExtension("test", element);
+    assertEquals(0, TestClass.ourCreationCount);
+  }
+
+  public static class TestClass {
+    public static int ourCreationCount = 0;
+
+    public TestClass() {
+      ourCreationCount++;
+    }
+  }
 }