What is done when MPT tries to update MPT? What does the INI section for this (in the 1.19 build of MPT) look like?
It looks like nothing because the update check does not exist in the official 1.19 release yet. It will come back with the next version. winhttp.dll has not been needed since 1.17.02.52 (when automatic checks were disabled).
In the next version, the INI section would look something like this...
[Update]
LastUpdateCheck=<date of last tried update>
UpdateCheckPeriod=<check period in days>
UpdateURL=<url to update server>
ShowUpdateHint=<has first automatic update been run and has an update hint been shown, do not edit>
SendGUID=<boolean value to enable or disable statistics>
Note to update check users: Starting from OpenMPT 1.19.01.05, the update URL has changed slightly, have a look at the first post to get the new URL. OpenMPT can now send an (anonymized) GUID together with each update check, which can help us in the future to collect very basic statistics (like f.e. how often is the program updated, or how many distinctive users are approximately using the update funcionatliy). No personal data can be collected through this, so I'd appreciate it if you didn't disable this option.