Open Radar

 
Summary:
Using an external keyboard, the key command ↓ (down arrow) does not work correctly in certain situations, jumps to unexpected locations.

Steps to Reproduce:
- Run the attached sample project on an iPad Simulator
- Tap into the UITextView on screen
- Using a long-press, place insertion point at the end of any wrapped line, e.g. after "ad" (this is important)
- Ensure the External keyboard is connected
- Press ↓ (down arrow)


Expected Results:
Tapping ↓ (down arrow) should move the insertion point down to a character below the insertion point.

Actual Results:
Tapping ↓ (down arrow) moves the insertion point to the beginning of the second-next line below!

Version:
iOS 9.3.1

Notes:
It seems as if the UITextInputTokenizer is not correctly respecting the selection affinity of the cursor placed in this way. The insertion point at the end of a *wrapped* line is ambiguous, since the respective character index also exists on the beginning of the next line. It seems the position is computed from that other position instead, which is incorrect.

Also:
- Using ↑ (up arrow) in the same situation is similarly broken and places the cursor at the beginning of the current line, suggesting the computation is broken in the just mentioned way
- The same happens when placing the cursor at the end of the line using ⌘→ (command-right), but this requires testing on a device

Configuration:
Any iOS device

Attachments:
'textedit v2.zip' was successfully uploaded. http://cl.ly/fk4d