fix(gitea): don't crash on empty body during pagination

lib/util/http/__snapshots__/gitea.spec.ts.snap

@@ -1,5 +1,30 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
+exports[`util/http/gitea handles pagination with empty response 1`] = `
+Array [
+  Object {
+    "headers": Object {
+      "accept": "application/json",
+      "accept-encoding": "gzip, deflate",
+      "host": "gitea.renovatebot.com",
+      "user-agent": "https://github.com/renovatebot/renovate",
+    },
+    "method": "GET",
+    "url": "https://gitea.renovatebot.com/api/v1/pagination-example-3",
+  },
+  Object {
+    "headers": Object {
+      "accept": "application/json",
+      "accept-encoding": "gzip, deflate",
+      "host": "gitea.renovatebot.com",
+      "user-agent": "https://github.com/renovatebot/renovate",
+    },
+    "method": "GET",
+    "url": "https://gitea.renovatebot.com/api/v1/pagination-example-3?page=2",
+  },
+]
+`;
+
 exports[`util/http/gitea supports pagination on data property 1`] = `
 Array [
   Object {

lib/util/http/gitea.spec.ts

@@ -67,4 +67,19 @@ describe(getName(__filename), () => {
     expect(res.body.data).toEqual(['abc', 'def', 'ghi', 'jkl', 'mno', 'pqr']);
     expect(httpMock.getTrace()).toMatchSnapshot();
   });
+  it('handles pagination with empty response', async () => {
+    httpMock
+      .scope(baseUrl)
+      .get('/pagination-example-3')
+      .reply(200, { data: ['abc', 'def', 'ghi'] }, { 'x-total-count': '5' })
+      .get('/pagination-example-3?page=2')
+      .reply(200, { data: [] });
+
+    const res = await giteaHttp.getJson<{ data: any }>('pagination-example-3', {
+      paginate: true,
+    });
+    expect(res.body.data).toHaveLength(3);
+    expect(res.body.data).toEqual(['abc', 'def', 'ghi']);
+    expect(httpMock.getTrace()).toMatchSnapshot();
+  });
 });

lib/util/http/gitea.ts

@@ -53,7 +53,12 @@ export class GiteaHttp extends Http<GiteaHttpOptions, GiteaHttpOptions> {
         resolvedUrl.searchParams.set('page', nextPage.toString());
 
         const nextRes = await super.request<T>(resolvedUrl.toString(), opts);
-        pc.push(...getPaginationContainer(nextRes.body));
+        const nextPc = getPaginationContainer(nextRes.body);
+        if (nextPc === null) {
+          break;
+        }
+
+        pc.push(...nextPc);
       }
     }