- Setting _q_readonly disables the timestamp check of the registered
online-help.qch file
- This enables displaying of Contents and Index of the online help,
even if the timestamp of online-help.qch is slightly different.
Differences in the timestamp can result from packing online-help.qch
in a cab file, when building the installer (1 or 2 seconds) or from
installing the file under a different timezone under Linux etc.
- Remark: Qt 5.14 or newer is required to display Contents or Index,
when the help files are readonly
Wolfgang Stöggl
Daniel Marjamäki