Bug 51895 Error when recovering javadoc archive path for a jar
1. add swt.jar to the Java build path of a project 2. open the properties dialog for this jar from the package explorer 3. change the javadoc location to : [x] javadoc in archive archive path: <path_to_eclipse>/plugins/org.eclipse.platform/doc/isv/doc.zip (in my case '/home/luc/host/eclipse/plugins/org.eclipse.platform/doc/isv/doc.zip') path within archive: reference/api 4. close the properties dialog 5. reopen the properties dialog The leading slash is missing, the dialog display the error 'the archive is missing '
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/preferences/JavadocConfigurationBlock.java
MessageDialog.openInformation(fShell, fTitle, fInvalidMessage); 
				return;
			}
			try {
				String protocol = location.getProtocol();
				if (protocol.equals("http") || protocol.equals("jar")) { 
					validateURL(location);
				} else if (protocol.equals("file")) { 
					validateFile(location);
				} else {
					MessageDialog.openInformation(fShell, fTitle, fUnable); 
				}
			} catch (MalformedURLException e) {
				MessageDialog.openInformation(fShell, fTitle, fUnable); 
			}
		}
		
		public void spawnInBrowser(URL url) {
			OpenBrowserUtil.open(url, fShell.getDisplay(), fTitle);
		}
		private void validateFile(URL location) throws MalformedURLException {
			File folder = new File(location.getFile());
			if (folder.isDirectory()) {
				File indexFile= new File(folder, "index.html"); 
				if (indexFile.isFile()) {				
					File packageList= new File(folder, "package-list"); 
					if (packageList.exists()) {
						if (MessageDialog.openConfirm(fShell, fTitle, fValidMessage)) { 
							spawnInBrowser(indexFile.toURL());
						}