MDL-62777 appears to have caused some core settings, and those of some 3rd party plugins, to no longer be set.

As far as core goes - tool_mobile no longer has several settings set.

This appears to be caused by some of the settings being wrapped in a IF check, that stops the settings nodes even existing prior to that setting being enabled.

Pre MDL-62777

• tool_mobile settings start with `enablemobilewebservice` unset, with a default of `1` and several settings that never get loaded until that is set.
• admin_apply_default_settings called
  • settings as they currently exist loaded
  • defaults set
• admin_apply_default_settings  called again
  • new settings now exist as `!empty($CFG->enablemobilewebservice` evaluates to true
  • defaults for those new settings are set

Post MDL-62777

• tool_mobile settings start with `enablemobilewebservice` unset, with a default of `1` and several settings that never get loaded until that is set.
• admin_apply_default_settings called
  • settings as they currently exist loaded
  • for each of those settings, build a list of defaults
  • defaults set
  • call admin_apply_default_settings - but only if we had new defaults applied

It looks like MDL-62777 covers the case where a default settings value may depend on another setting - but not where a settings even "existing" in the settings tree depends on another setting.