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
fArchivePathField.setText(insidePath);
			fArchiveField.setText(jarPath);
		} else {
			fURLField.setText(initialValue);
		}		
	}
		
	public void setFocus() {
		fURLField.postSetFocusOnDialogField(fShell.getDisplay());
	}
	
	public void performDefaults() {
		initializeSelections();
	}
	
	public URL getJavadocLocation() {
		if (fIsForSource || fURLRadioButton.isSelected()) {
			return fURLResult;
		}
		return fArchiveURLResult;
	}
		
	private class EntryValidator implements Runnable {
		private String fInvalidMessage= PreferencesMessages.getString("JavadocConfigurationBlock.InvalidLocation.message"); 
		private String fValidMessage= PreferencesMessages.getString("JavadocConfigurationBlock.ValidLocation.message"); 
		private String fTitle=  PreferencesMessages.getString("JavadocConfigurationBlock.MessageDialog.title"); 
		private String fUnable= PreferencesMessages.getString("JavadocConfigurationBlock.UnableToValidateLocation.message"); 
		public void run() {
			URL location= getJavadocLocation();
			if (location == null) {