prompted to save non-existent changes when opening a file immediately after launching

[precurejunkie]

Steps to reproduce:

1. Double-click the Aegisub application icon in Finder
2. Choose File > Open Subtitles... from the menu
3. Choose the subtitle file you want to open and click Open

Actual results:

• prompt appears reading "Unsaved changes" "Save before continuing?"

Expected results:

• Since I haven't done anything except launch the app, there should be nothing to save, and I should not get this prompt.

Alternate steps to reproduce:

1. Drag an .ass file onto the Aegisub application icon in Finder

• The first thing Aegisub does after launching in this case is prompt you to save the unsaved changes.

[nielsm]

Known, and we know the root cause of it: On Mac, when the initial value of the Style selection dropdown is set in the main editing area, it causes a "change" event, which it does not on any other platform. This change event in turn causes the file to be marked as changed, even though it isn't.

Assigning this to kollivier, since he probably has a better chance of figuring out the best solution, and he discovered the root cause in the first place.

[kollivier]

This has been fixed in wx trunk, if you update your wx (or Aegisub releases using a newer wx build) then it will fix the problem.