NPE when the TagRouterRule addresses config is null

[web1992]

• I have searched the issues of this repository and believe that this is not a duplicate.
• I have checked the FAQ of this repository and believe that this is not a duplicate.

Environment

• Dubbo version: 2.7.1
• Operating System version: Windows
• Java version: 1.8

Steps to reproduce this issue

When I config TagRouter like this (in Dubbo admin):

enabled: true
force: false
runtime: false
tags:
  - name: tag1
    addresses: null
  - name: tag2
    addresses: null

Actual Result

Then the java.lang.NullPointerException was caused

java.lang.NullPointerException
	at org.apache.dubbo.rpc.cluster.router.tag.model.TagRouterRule.lambda$init$2(TagRouterRule.java:55)
	at java.util.ArrayList.forEach(ArrayList.java:1257)
	at org.apache.dubbo.rpc.cluster.router.tag.model.TagRouterRule.init(TagRouterRule.java:53)
	at org.apache.dubbo.rpc.cluster.router.tag.model.TagRuleParser.parse(TagRuleParser.java:42)

I think we should add NPE check in TagRouterRule or check addresses in Dubbo admin

tags.forEach(tag -> {
    tagnameToAddresses.put(tag.getName(), tag.getAddresses());
   // check  tag.getAddresses() not null
    tag.getAddresses().forEach(addr -> {
        List<String> tagNames = addressToTagnames.computeIfAbsent(addr, k -> new ArrayList<>());
        tagNames.add(tag.getName());
    });
});

[CrazyHZM]

Can you submit a PR to fix it?

[web1992]

@CrazyHZM I have send one PR

[CrazyHZM]

Thank you, I have already dealt with it.