Motivation / Problem

@LordAro had an ini-file that crashed the game upon save. Investigation showed I fucked up IniGroup::RemoveItem ;)

Description

There are a few things going on here, but mostly last_item is a shitty name for a pointer to the ->next of the real last item. I drew some wrong conclusions because of that, resulting in a broken implementation.

Now when the last item of a group is removed, last_item points to the next of the previous value, keeping the group in a valid state.

Limitations

Checklist for review

Some things are not automated, and forgotten often. This list is a reminder for the reviewers.

• The bug fix is important enough to be backported? (label: 'backport requested')
• This PR affects the save game format? (label 'savegame upgrade')
• This PR affects the GS/AI API? (label 'needs review: Script API')
  • ai_changelog.hpp, gs_changelog.hpp need updating.
  • The compatibility wrappers (compat_*.nut) need updating.
• This PR affects the NewGRF API? (label 'needs review: NewGRF')
  • newgrf_debug_data.h may need updating.
  • PR must be added to API tracker