Bug 42655 SourceAttachmentBlock does not use dialog font for all widgets [dialogs] [build path]
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/wizards/buildpaths/SourceAttachmentBlock.java
} else {
				newEntries.add(curr);
			}
		}
		if (!found) {
			if (newEntry.getSourceAttachmentPath() == null || !putJarOnClasspathDialog(shell)) {
				return;
			}
			
			newEntries.add(newEntry);			
		}
		IClasspathEntry[] newClasspath= (IClasspathEntry[]) newEntries.toArray(new IClasspathEntry[newEntries.size()]);
		jproject.setRawClasspath(newClasspath, monitor);
	}
	
	private boolean putJarOnClasspathDialog(Shell shell) {
		final boolean[] result= new boolean[1];
		shell.getDisplay().syncExec(new Runnable() {
			public void run() {
				String title= NewWizardMessages.getString("SourceAttachmentBlock.putoncpdialog.title"); 
				String message= NewWizardMessages.getString("SourceAttachmentBlock.putoncpdialog.message"); 
				result[0]= MessageDialog.openQuestion(JavaPlugin.getActiveWorkbenchShell(), title, message);
			}
		});
		return result[0];
	}
	
	
}