An inactive user shouldn't be able to be added as a collaborator (#4535)

* an inactive user shouldn't be able to be a collaborator

* use translated error message

* add active user check when adding a new collaborator via the api

* fix translation text

* added collaborator test

* improvee testcases

routers/repo/setting.go

@@ -381,6 +381,12 @@ func CollaborationPost(ctx *context.Context) {
 		return
 	}
 
+	if !u.IsActive {
+		ctx.Flash.Error(ctx.Tr("repo.settings.add_collaborator_inactive_user"))
+		ctx.Redirect(setting.AppSubURL + ctx.Req.URL.Path)
+		return
+	}
+
 	// Organization is not allowed to be added as a collaborator.
 	if u.IsOrganization() {
 		ctx.Flash.Error(ctx.Tr("repo.settings.org_not_allowed_to_be_collaborator"))

routers/repo/settings_test.go

@@ -97,6 +97,30 @@ func TestCollaborationPost(t *testing.T) {
 	assert.True(t, exists)
 }
 
+func TestCollaborationPost_InactiveUser(t *testing.T) {
+
+	models.PrepareTestEnv(t)
+	ctx := test.MockContext(t, "user2/repo1/issues/labels")
+	test.LoadUser(t, ctx, 2)
+	test.LoadUser(t, ctx, 9)
+	test.LoadRepo(t, ctx, 1)
+
+	ctx.Req.Form.Set("collaborator", "user9")
+
+	repo := &context.Repository{
+		Owner: &models.User{
+			LowerName: "user2",
+		},
+	}
+
+	ctx.Repo = repo
+
+	CollaborationPost(ctx)
+
+	assert.EqualValues(t, http.StatusFound, ctx.Resp.Status())
+	assert.NotEmpty(t, ctx.Flash.ErrorMsg)
+}
+
 func TestCollaborationPost_AddCollaboratorTwice(t *testing.T) {
 
 	models.PrepareTestEnv(t)