Originally Posted by sriggins
In fact, how do you turn this OFF? Wow you can easily accidentally complete an entire project with NO feedback.
First one that comes to mind. HAve project selected, press command-space for spotlight, but kinda miss the command key, and if you are looking up at the spotlight corner, nothing happens, you shrug, press it again, oh good, spotlight, then 2 days later, "what the heck happened to my project!"
This is theoretically possible, but OmniOutliner and OmniFocus both use this mechanism, and in my years of using both apps, I don't think this has ever actually happened.
You have to be in row-selection-but-not-editing mode for it to happen; otherwise you'll just get a space character in whatever cell you're editing.
For the project to disappear, you'd have to be using the 'Active' projects filter selected - with the 'Remaining' filter, the project will get a strikethrough style applied but remain visible.
Ultimately, you're correct - in a very specific set of circumstances, the feature could cause unintended behavior. I'm not sure there's an easy solution, though: removing the feature is a no-go, and notifying the user every time they mark something complete is going to annoy more folks than it helps.
Theoretically, we could make a preference for this, but do that across the board and you end up with preference panes as numerous/complex as Eudora. Which is not a good thing, in my personal opinion. ;-)