Spurious no-op edit occurs when right-clicking repeatedly

[peterflynn]

1. Open a JS file
2. Right-click in the middle of any word
3. Without moving the mouse, right-click two more times

Result: On the third right-click, the word becomes deselected and the file is marked dirty, although the text has not changed at all. If you undo, the dirty flag goes away, but the text again does not change.

Expected: Third click behaves exactly the same as the first two.

This appears to be another case of #1129, except that this one didn't repro in sprint-9 so it seems to be connected to context menus somehow. However, it seems hard to hit in practice and the consequences aren't dire so I don't think it should block Sprint 10.

[pthiess]

Reviewed, related to #1111

[redmunds]

Added Mac-only tag. Interesting that this does not seem to reproduce in brackets-shell. @peterflynn can you reproduce this in brackets-shell? If not, then it may not be worth the effort.

[peterflynn]

Same as #1129 -- it still repros in brackets-app but not in brackets-shell. CEF must have been sending bad events to CodeMirror.

[redmunds]

Closing