Bug 103927 [build path] External jar Dialog cannot set both Javadoc Location and Java Source Attachment in one iteration
Add an external jar to the project. From the context menu of the jar select properties. Select Javadoc location, browse to the desired location. Select Java Source Attachment. Browse to an external file. Press OK. From the context menu of the jar select properties again. Javadoc location is empty. (At this point it can be entered again without problems)
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/wizards/buildpaths/SourceAttachmentBlock.java
return Path.fromOSString(res).makeAbsolute();
		}
		return null;
	}	
	
	/*
	 * Opens a dialog to choose an internal jar.
	 */	
	private IPath chooseInternal() {
		String initSelection= fFileNameField.getText();
		
		ViewerFilter filter= new ArchiveFileFilter((List) null, false);
		ILabelProvider lp= new WorkbenchLabelProvider();
		ITreeContentProvider cp= new WorkbenchContentProvider();
		IResource initSel= null;
		if (initSelection.length() > 0) {
			initSel= fWorkspaceRoot.findMember(new Path(initSelection));
		}
		if (initSel == null) {
			initSel= fWorkspaceRoot.findMember(fEntry.getPath());
		}
		FolderSelectionDialog dialog= new FolderSelectionDialog(getShell(), lp, cp);
		dialog.setAllowMultiple(false);
		dialog.addFilter(filter);
		dialog.setTitle(NewWizardMessages.SourceAttachmentBlock_intjardialog_title); 
		dialog.setMessage(NewWizardMessages.SourceAttachmentBlock_intjardialog_message); 
		dialog.setInput(fWorkspaceRoot);
		dialog.setInitialSelection(initSel);
		if (dialog.open() == Window.OK) {
			IResource res= (IResource) dialog.getFirstResult();