[MM-18831] Trim whitespace of Display Name when channel is cre… (#12380)

app/channel.go

@@ -223,6 +223,8 @@ func (a *App) RenameChannel(channel *model.Channel, newChannelName string, newDi
 }
 
 func (a *App) CreateChannel(channel *model.Channel, addMember bool) (*model.Channel, *model.AppError) {
+	channel.DisplayName = strings.TrimSpace(channel.DisplayName)
+
 	sc, err := a.Srv.Store.Channel().Save(channel, *a.Config().TeamSettings.MaxChannelsPerTeam)
 	if err != nil {
 		return nil, err

app/channel_test.go

@@ -254,6 +254,14 @@ func TestCreateChannelPrivateCreatesChannelMemberHistoryRecord(t *testing.T) {
 	assert.Equal(t, th.BasicUser.Id, histories[0].UserId)
 	assert.Equal(t, privateChannel.Id, histories[0].ChannelId)
 }
+func TestCreateChannelDisplayNameTrimsWhitespace(t *testing.T) {
+	th := Setup(t).InitBasic()
+	defer th.TearDown()
+
+	channel, err := th.App.CreateChannel(&model.Channel{DisplayName: "  Public 1  ", Name: "public1", Type: model.CHANNEL_OPEN, TeamId: th.BasicTeam.Id}, false)
+	require.Nil(t, err)
+	require.Equal(t, channel.DisplayName, "Public 1")
+}
 
 func TestUpdateChannelPrivacy(t *testing.T) {
 	th := Setup(t).InitBasic()