fix duplicate loading of changesets on first page load

scm-ui/src/repos/modules/branches.js

@@ -97,14 +97,12 @@ function extractBranchesFromPayload(payload: any) {
 
 // Selectors
 
-const empty = [];
-
 export function getBranches(state: Object, repository: Repository) {
   const key = createKey(repository);
   if (state.branches[key]) {
     return state.branches[key];
   }
-  return empty;
+  return null;
 }
 
 export function getBranch(

scm-ui/src/repos/modules/branches.test.js

@@ -157,6 +157,11 @@ describe("branches", () => {
       expect(one).toBe(two);
     });
 
+    it("should return null, if no branches for the repository available", () => {
+      const branches = getBranches({ branches: {} }, repository);
+      expect(branches).toBeNull();
+    });
+
     it("should return single branch by name", () => {
       const branch = getBranch(state, repository, "branch1");
       expect(branch).toEqual(branch1);