Created attachment 185407 [details]
Spreadsheet with the bug manifesting

Do the following:

1. Create a new spreadsheet
2. Set the direction of cell A1 to RTL
3. Type in "hello world"
4. Select only the word "world" within the edited cell text
5. Insert a hyperlink (e.g. using Ctrl+K or Insert > Hyperlink on the menu) to some arbitrary URL, e.g. "foo"

Expected results: 

* After step (3.), the word "hello" appears to the left of the word "world".
* After step (5.), the word "hello" appears to the left of the word "world".

Actual results:

* After step (3.), the word "hello" appears to the left of the word "world".
* After step (5.), the word "hello" appears to the RIGHT of the word "world".

It seems that the hyperlinking breaks the LTR run, and the two runs/spans/objects are placed according to the cell direction

Note: The sheet direction doesn't matter (which is ok).