Fix handling of reports with no labels

because go, and because nil != [], and because my testing wasn't adequate.

src/github.com/matrix-org/rageshake/submit.go

@@ -123,7 +123,7 @@ func (s *submitServer) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 
 	resp, err := s.saveReport(req.Context(), *p, reportDir, listingURL)
 	if err != nil {
-		log.Println("Error handling report", err)
+		log.Println("Error handling report submission:", err)
 		http.Error(w, "Internal error", 500)
 		return
 	}
@@ -478,10 +478,16 @@ func buildGithubIssueRequest(p parsedPayload, listingURL string) github.IssueReq
 	}
 
 	body := bodyBuf.String()
+
+	labels := p.Labels
+	// go-github doesn't like nils
+	if labels == nil {
+		labels = []string{}
+	}
 	return github.IssueRequest{
 		Title:  &title,
 		Body:   &body,
-		Labels: &p.Labels,
+		Labels: &labels,
 	}
 }
 

src/github.com/matrix-org/rageshake/submit_test.go

@@ -63,6 +63,9 @@ func TestEmptyJson(t *testing.T) {
 	if p == nil {
 		t.Fatal("parseRequest returned nil")
 	}
+	if len(p.Labels) != 0 {
+		t.Errorf("Labels: got %#v, want []", p.Labels)
+	}
 }
 
 // check that we can unpick the json submitted by the android clients
@@ -137,14 +140,6 @@ Content-Disposition: form-data; name="user_agent"
 
 Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/57.0.2987.133 Safari/537.36
 ------WebKitFormBoundarySsdgl8Nq9voFyhdO
-Content-Disposition: form-data; name="label"
-
-label1
-------WebKitFormBoundarySsdgl8Nq9voFyhdO
-Content-Disposition: form-data; name="label"
-
-label2
-------WebKitFormBoundarySsdgl8Nq9voFyhdO
 Content-Disposition: form-data; name="test-field"
 
 Test data
@@ -195,9 +190,8 @@ func checkParsedMultipartUpload(t *testing.T, p *parsedPayload) {
 	if len(p.Data) != 3 {
 		t.Errorf("Data length: got %d, want 3", len(p.Data))
 	}
-	wantedLabels := []string{"label1", "label2"}
-	if !stringSlicesEqual(p.Labels, wantedLabels) {
-		t.Errorf("Labels: got %v, want %v", p.Labels, wantedLabels)
+	if len(p.Labels) != 0 {
+		t.Errorf("Labels: got %#v, want []", p.Labels)
 	}
 	wanted = "Test data"
 	if p.Data["test-field"] != wanted {
@@ -217,6 +211,32 @@ func checkParsedMultipartUpload(t *testing.T, p *parsedPayload) {
 	}
 }
 
+func TestLabels(t *testing.T) {
+	body := `------WebKitFormBoundarySsdgl8Nq9voFyhdO
+Content-Disposition: form-data; name="label"
+
+label1
+------WebKitFormBoundarySsdgl8Nq9voFyhdO
+Content-Disposition: form-data; name="label"
+
+label2
+------WebKitFormBoundarySsdgl8Nq9voFyhdO--
+`
+	p, _ := testParsePayload(t, body,
+		"multipart/form-data; boundary=----WebKitFormBoundarySsdgl8Nq9voFyhdO",
+		"",
+	)
+
+	if p == nil {
+		t.Fatal("parseRequest returned nil")
+	}
+
+	wantedLabels := []string{"label1", "label2"}
+	if !stringSlicesEqual(p.Labels, wantedLabels) {
+		t.Errorf("Labels: got %v, want %v", p.Labels, wantedLabels)
+	}
+}
+
 func stringSlicesEqual(got, want []string) bool {
 	if len(got) != len(want) {
 		return false