Open Radar

 
Summary:
Hi!

I noticed xcode9 deleting stuff unexpectedly when editing today.  I managed to track this down to:

* double-click a word to select
* immediately type after the click
* extra text (a newline in this case) gets selected after the initial selection goes away, and then gets deleted on the next keystroke.

See movie at https://www.dropbox.com/s/redacted/double-click-selection.mp4?dl=0

There's a massively slowed down section that shows what's going on.

Steps to Reproduce:
This is very timing dependent.

* double click a word to select it
* immediately start typing after releasing the mouse button. As in scalosian-water fast.

Expected Results:
* the word is highlighted
* typing commences
* the word disappears and is replaced with new typing

Observed Results:
* the word is highlighted
* typing commences
* the word disappears and is replaced with the first letter
* the next character (or the next newline) gets unexpectedly selected 
* the next letter typed deletes this new selection

Version:
10.12.5 (16F73)
Version 9.0 beta 3 (9M174d)

Notes:


Configuration:
Didn't recall having this problem with the old xcode8 editor.