docs(hostRules): document current matchHost behaviour if a port is supplied

docs/usage/configuration-options.md

@@ -1190,6 +1190,23 @@ A preset alternative to the above is:
 }
 ```
 
+To match specific ports you have to add a protocol to `matchHost`:
+
+```json
+{
+  "hostRules": [
+    {
+      "matchHost": "https://domain.com:9118",
+      "enabled": false
+    }
+  ]
+}
+```
+
+<!-- prettier-ignore -->
+!!! warning
+    Using `matchHost` without a protocol will lead to a behaviour as there is no `matchHost` configuration at all.
+
 <!-- prettier-ignore -->
 !!! note
     Disabling a host is only 100% effective if added to self-hosted config.

lib/util/host-rules.spec.ts

@@ -235,6 +235,26 @@ describe('util/host-rules', () => {
       expect(find({ url: 'httpsdomain.com' }).token).toBeUndefined();
     });
 
+    it('matches on matchHost with port', () => {
+      add({
+        matchHost: 'https://domain.com:9118',
+        token: 'def',
+      });
+      expect(find({ url: 'https://domain.com:9118' }).token).toBe('def');
+      expect(find({ url: 'https://domain.com' }).token).toBeUndefined();
+      expect(find({ url: 'httpsdomain.com' }).token).toBeUndefined();
+    });
+
+    it('host with port is interpreted as empty', () => {
+      add({
+        matchHost: 'domain.com:9118',
+        token: 'def',
+      });
+      expect(find({ url: 'https://domain.com:9118' }).token).toBe('def');
+      expect(find({ url: 'https://domain.com' }).token).toBe('def');
+      expect(find({ url: 'httpsdomain.com' }).token).toBe('def');
+    });
+
     it('matches on hostType and endpoint', () => {
       add({
         hostType: NugetDatasource.id,