QCommandLineParser not processing option value if value name is not supplied

When command line options are parsed by the command line parser if a value name isn't supplied the parsing will fail and the option will not have a value. In my opinion it shouldn't be required to supply a third parameter for the option constructor (value name), because it's only relevant for the display of the option's help text. But even if it is a requirement, it should be made explicit in the documentation.

Currently the docs read:
In addition, the valueName can be set if the option expects a value. The default value for the option is set to defaultValue.

If valueName is indeed a requirement, then it should read:
In addition, the valueName can should/must be set if the option expects a value. The default value for the option is set to defaultValue.

You can find attached a MWE that reproduces the issue.

PS.
Also present with about a week old dev branch build.