Do not encode "," when redirecting /projects/ -> /repos/

Bug: Issue 11096
Change-Id: Id3eb92254f25e8e86568be50c11e60d1a6835af9

polygerrit-ui/app/elements/core/gr-router/gr-router.js

@@ -1092,11 +1092,16 @@
     },
 
     _handleProjectsOldRoute(data) {
+      let params = '';
       if (data.params[1]) {
-        this._redirect('/admin/repos/' + encodeURIComponent(data.params[1]));
+        params = encodeURIComponent(data.params[1]);
-      } else {
+        if (data.params[1].includes(',')) {
-        this._redirect('/admin/repos');
+          params =
+              encodeURIComponent(data.params[1]).replace('%2C', ',');
+        }
       }
+
+      this._redirect(`/admin/repos/${params}`);
     },
 
     _handleRepoCommandsRoute(data) {

polygerrit-ui/app/elements/core/gr-router/gr-router_test.html

@@ -1100,6 +1100,28 @@ limitations under the License.
       });
 
       suite('repo routes', () => {
+        test('_handleProjectsOldRoute', () => {
+          const data = {params: {}};
+          element._handleProjectsOldRoute(data);
+          assert.isTrue(redirectStub.calledOnce);
+          assert.equal(redirectStub.lastCall.args[0], '/admin/repos/');
+        });
+
+        test('_handleProjectsOldRoute test', () => {
+          const data = {params: {1: 'test'}};
+          element._handleProjectsOldRoute(data);
+          assert.isTrue(redirectStub.calledOnce);
+          assert.equal(redirectStub.lastCall.args[0], '/admin/repos/test');
+        });
+
+        test('_handleProjectsOldRoute test,branches', () => {
+          const data = {params: {1: 'test,branches'}};
+          element._handleProjectsOldRoute(data);
+          assert.isTrue(redirectStub.calledOnce);
+          assert.equal(
+              redirectStub.lastCall.args[0], '/admin/repos/test,branches');
+        });
+
         test('_handleRepoRoute', () => {
           const data = {params: {0: 4321}};
           assertDataToParams(data, '_handleRepoRoute', {