[mythtv-commits] [MythTV/mythtv] c12871: Allow some channel, string settings to be cleared.

[David Engel]

  Branch: refs/heads/master
  Home:   https://github.com/MythTV/mythtv
  Commit: c12871f52a1d72fb6ab9bab903fd6275136124b1
      https://github.com/MythTV/mythtv/commit/c12871f52a1d72fb6ab9bab903fd6275136124b1
  Author: David Engel <dengel at mythtv.org>
  Date:   2022-08-26 (Fri, 26 Aug 2022)

  Changed paths:
    M mythtv/libs/libmythtv/channelutil.cpp

  Log Message:
  -----------
  Allow some channel, string settings to be cleared.

ChannelUtil::UpdateChannel() incorrectly prevents some channel
seetings from being cleared/set to empty strings by checking for
isEmpty().  This primarily affects the services API.  Fix the problem
by checking isNull() instead.  When no value is specified via the API,
a null (not NUL) string is passed in and no change is applied.  When
an empty string is specified via the API, however, a non-null (but
empty) string is passed in and the value is correctly cleared.