571352 - <select multiple> does not reset the anchor <option> properly when the anchor is removed

Status: RESOLVED FIXED

(Core :: Layout: Form Controls, defect)

Description

[Frank Yan (:fryn)]

Attachment: simple testcase

When selecting a range of <option> elements from a <select multiple> and then removing the anchor of that selection range, the anchor is moved to the previous <option> element, which often results in unexpected behavior.

*** This bug is probably not limited to just <select multiple> elements, but I have not had the time to investigate. If you would like to, please do! ***

Steps to reproduce:

1. Open up the simple testcase attached to this bug.
2. Click the <option> labelled 1.
3. Shift+click the <option> labelled 4. (Options 1-4 are now selected.)
4. Click the button labelled "Remove...". (Options 2-4 are now selected.)
5. Shift+click the <option> labelled 5.

Expected results:

Options 2-5 are now selected, because the anchor element should be been set to the closest <option> element inside the selection range (which is option 2 in this case).

Actual results:

Options 0,2-5 are now selected.

Notes:

While WebKit does not have this exact bug, it does has non-intuitive behavior of this writing. To demonstrate in Webkit: click option 5; then shift+click option 2; then remove option 5; then shift+click option 1. Now options 1 and 2 are selected. Why? WebKit resets the anchor to the first/top (rather than closest) element in the selection range.

Comment 1

[Mats Palmgren (inactive)]

Preserving the anchor..focus direction and range so that includes the same
options (except for the removed one), as before the removal seems reasonable.

Comment 2

[Mats Palmgren (inactive)]

Attachment: Patch rev. 1

Comment 3

[Boris Zbarsky [:bzbarsky]]

Comment on attachment 450852 [details] [diff] [review]
Patch rev. 1

r=bzbarsky

Comment 4

[Mats Palmgren (inactive)]

http://hg.mozilla.org/mozilla-central/rev/a84d22a38a6e