Menu crashes if user selects Editor -> (edits something) then hits escape twice

[chris]

See summary. Current as of git master, 2011-05-01.

[chris]

Actually crashes just on escape from editor (when switching back to menu). Also only occurs if you click the 'default' scenario button then hit edit. Just hitting edit does not cause crash.

[knowknowledge]

I believe that this is fixed in the current master branch.

While adding the Actions, I noticed an interesting potential bug:

While executing code in activated by a button, the code can close (and therefore delete) the button that is currently executing that code. This means that any code executed after an Action is Activated() that attempts to access the object can trigger a segfault.

There are two solutions to this problem that I can think of:
1: All code that could potentially activate an action must be at the end of the function.
2: No Widgets should get deleted immediately, but should persist until all Widget actions have completed.

Solution (1) is a bit difficult because there are some Widget functions that have multiple exit points.
Solution (2) requires some extra tracking, but is definitely possible.

[chris]

Valgrind output log. Invalid read of size 1 in UI::Draw is the bug.

[chris]

Added an 'if' statement to my git repo at knowknowledge's advice to avoid the bug. Added a FIXME as something is still clearly wrong.

[knowknowledge]

The Screen Swap was not flushing the deferred list, so floating widgets were neither drawn nor forgotten. Each time that one of the screens with an open Dropdown, the drawing of the Dropdown would be deferred, but not flushed. This meant that there were several stale Dropdown pointers in the deferred list caused by Swapping screens. If the UI is Closed before it is drawn, then those stale pointers will be accessed incorrectly.

Fixed in: 0f1dc8d26ef3d2e522f4dfae7e0f6c1682d2f060