On Oct 3, 2018, at 10:19 AM, Guy Harris <guy@xxxxxxxxxxxx> wrote:
> If you were to create a global preferences file that sets it, that will forcibly turn that setting off for all users who don't have a personal preferences file or whose personal preferences file doesn't explicitly set it. "Set" is the default for that preference, so newer versions of Wireshark will only have an entry for it in the personal preferences file if the user has un-set it. (Older versions would write out preference settings even if they *don't* match the default.)
...
> That way, the initial setting for that option would be "unchecked".
...and the user won't be able to override that by editing their preferences, because the code in Wireshark that implements
> "Set" is the default for that preference, so newer versions of Wireshark will only have an entry for it in the personal preferences file if the user has un-set it.
treats the default as the initial setting in the dissector code; it doesn't take into account any changes made by the global preferences file.
This is arguably a bug.
And, for general reference on all OSes:
The location of the global preference file is, on UN*Xes, the data file directory for the Wireshark installation.
On all but one UN*X, this would probably be /usr/share/wireshark or /usr/local/share/wireshark; it might be different if whoever built Wireshark explicitly configured it to be differently, for example if they built a package to be installed under /opt.
On macOS, Wireshark is normally built as an app bundle, and the data file directory is the Contents/Resources/share/wireshark/preferences subdirectory of the top-level app bundle directory.
On Windows, the data file directory is the installation directory containing the Wireshark (and other) executables, e.g. C:\Program Files\Wireshark.