Bug 371022

Description Slava Kabanovich 2012-02-08 17:51:48 EST

Build Identifier: Version: 3.7.0 Build id: I20110613-1736

When a Dynamic Web Project expanded in Project Explorer is deleted, various exception may be logged, that have common line in stack trace: 
at org.eclipse.jst.jee.ui.internal.navigator.JEE5ContentProvider.getCachedContentProvider(JEE5ContentProvider.java:92)

The issue may be not 100% reproducible as it depends on concurrent threads that delete project and refresh Project Explorer; manipulating threads in debugger, it is possible to ensure the failure.

I attach two exceptions: 
1) java.lang.IllegalStateException: The project <P/Test> is not accessible. at org.eclipse.jst.jee.model.internal.JEE5ModelProvider.getModelResource(JEE5ModelProvider.java:148) - it is most probable;

2) java.lang.NullPointerException at org.eclipse.jst.jee.ui.internal.navigator.JEE5ContentProvider.getCachedModelProvider(JEE5ContentProvider.java:76) - I have seen it just once.

Method JEE5ContentProvider.getCachedContentProvider() looks for a AbstractGroupProvider in groupContentProviders for the project. If project is expanded in Project Explorer, the group content provider is usually found, excepting when the map is accessed after PRE_DELETE event that removes the group content provider for the project.
When the group content provider is found, IllegalStateException is caught without logging.
When the group content provider is not found, because PRE_DELETE event already removed it from the cache, IllegalStateException is not caught, instead project is tested by isAccessible(). 

The following succession leads to the failure:
1) User requests deletion of a project;
2) Refresh of Project Explorer starts Web25ContentProvider;
3) PRE_DELETE event clears JEE5ContentProvider.groupContentProviders;
4) In JEE5ContentProvider.getCachedContentProvider(), test  project.isAccessible() returns true and getNewContentProviderInstance() is called;
5) Deletion of the project is completed;
6) In JEE5ModelProvider.getModelResource() test project.isAccessible() returns false and IllegalStateException is thrown.



Reproducible: Always

Steps to Reproduce:
1. Create Dynamic Web Project
2. Expand it in Project Explorer
3. Delete project - check "Delete project contents on disk"