Bug 330553 [Import/Export] Importing a project that exists in workspace location merges the contents
(1) Create a project in the default location (2) Export it to an archive (3) Delete it (but don't choose the option to delete from disk) (4) Make some changes in the <workspace root>/<project> directory (4) Import the archive you exported in step 2 This results in files from both the archive and directory. If the directory already has a file thats available in the archive, then it doesn't modify it. Ideally we shouldn't be allowing the import at all.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/wizards/datatransfer/WizardProjectsImportPage.java
private boolean isProjectInWorkspace(String projectName) {
		if (projectName == null) {
			return false;
		}
		IProject[] workspaceProjects = getProjectsInWorkspace();
		for (int i = 0; i < workspaceProjects.length; i++) {
			if (projectName.equals(workspaceProjects[i].getName())) {
				return true;
			}
		}
		return false;
	}
	/**
	 * Use the dialog store to restore widget values to the values that they
	 * held last time this wizard was used to completion, or alternatively,
	 * if an initial path is specified, use it to select values.
	 * 
	 * Method declared public only for use of tests.
	 */
	public void restoreWidgetValues() {
				
		
		
		IDialogSettings settings = getDialogSettings();
		if (settings != null) {
			
			copyFiles = settings.getBoolean(STORE_COPY_PROJECT_ID);
			copyCheckbox.setSelection(copyFiles);
		}