Return 404 when deleting non-existent branch through api

Author: hramrach

services/repository/branch.go

@@ -609,6 +609,11 @@ func DeleteBranch(ctx context.Context, doer *user_model.User, repo *repo_model.R
 				return fmt.Errorf("DeleteBranch: %v", err)
 			}
 		}
+		if notExist {
+			return git.ErrBranchNotExist{
+				Name: branchName,
+			}
+		}
 		if branchCommit == nil {
 			return nil
 		}
@@ -618,6 +623,11 @@ func DeleteBranch(ctx context.Context, doer *user_model.User, repo *repo_model.R
 		return err
 	}
 
+	if notExist {
+		return git.ErrBranchNotExist{
+			Name: branchName,
+		}
+	}
 	if branchCommit == nil {
 		return nil
 	}

tests/integration/api_branch_test.go

@@ -402,6 +402,7 @@ func TestAPIBranchProtection(t *testing.T) {
 	// Test branch deletion
 	testAPIDeleteBranch(t, "master", http.StatusForbidden)
 	testAPIDeleteBranch(t, "branch2", http.StatusNoContent)
+	testAPIDeleteBranch(t, "branch2", http.StatusNotFound)
 }
 
 func TestAPICreateBranchWithSyncBranches(t *testing.T) {