Not saving settings without opening Advanced menu once
Spark is never writing values for settings on the Advanced menu (on Login screen) to spark.properties file, if a user never opens it. This makes it hard to change the defaults for these settings without affecting existing users (say change Accept all certificates to disabled instead of enabled by default), as the settings are never saved. This works fine for the settings enabled by default as Spark enables them every time a user runs Spark (on the fly). But if a setting is changed to be false by default, it will be false, although it was true in the previous version. One can find the current behavior beneficial in some scenarios, but it creates inconsistency (some users have these settings saved, because they picked into that menu, others don't). And as other setting are saved into spark.properties even without opening the Preferences menu, i think Advanced settings should be automatically saved also.
Fixed with PR #266 using the following solution:
After a successful login, all default values normally found under “Advanced Connections Preferences” dialogs are written to spark.properties file – whether the user visited the “Advanced” dialogs or not. It will not overwrite any keys that may have been written to that file previously.