Bug 255172 [Import/Export] Warning message in the import wizard is not so helpful
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/wizards/datatransfer/WizardProjectsImportPage.java
private void setProjectName() {
			try {
				if (projectArchiveFile != null) {
					InputStream stream = structureProvider
							.getContents(projectArchiveFile);
					
					if (stream == null) {
						if (projectArchiveFile instanceof ZipEntry) {
							IPath path = new Path(
									((ZipEntry) projectArchiveFile).getName());
							projectName = path.segment(path.segmentCount() - 2);
						} else if (projectArchiveFile instanceof TarEntry) {
							IPath path = new Path(
									((TarEntry) projectArchiveFile).getName());
							projectName = path.segment(path.segmentCount() - 2);
						}
					} else {
						description = IDEWorkbenchPlugin.getPluginWorkspace()
								.loadProjectDescription(stream);
						stream.close();
						projectName = description.getName();
					}
				}
				
				if (projectName == null) {
					IPath path = new Path(projectSystemFile.getPath());
					
					
					if (isDefaultLocation(path)) {
						projectName = path.segment(path.segmentCount() - 2);