1472074 - Selection behavior of multiple tabs by Shift-click is incompatible to Google Chrome

Status: NEW

Description

[YUKI "Piro" Hiroshi]

# Abstract

Shift-click on tabs now selects multiple tabs by range after the bug 1458013.
However, the behavior is different from Google Chrome's one.

# Steps to reproduce

 1. Start Nightly 63.
 2. Go to "about:config" and set "browser.tabs.multiselect" to "true".
 3. Prepare five tabs: A, B, C, D and E.
 4. Activate the tab C. Now you see tabs like:
    - A
    - B
    - C(active)
    - D
    - E
 5. Shift-click on the tab E. Then three tabs C, D, and E are selected.
    Now you see tabs like:
    - A
    - B
    - C(active/highlighted)
    - D(highlighted)
    - E(highlighted)
 6. Shift-click on the tab A.

# Expected result

D and E are dehighlighted and only A, B and C are highlighted, like:

    - A(highlighted)
    - B(highlighted)
    - C(active/highlighted)
    - D
    - E

# Actual result

C and D are not dehighlighted and all of five tabs are highlighted, like:

    - A(highlighted)
    - B(highlighted)
    - C(active/highlighted)
    - D(highlighted)
    - E(highlighted)

# Environment:

I've verified that Google Chrome 67.0.3396.62 produces the expected result I wrote above.

My Firefox is:

 * Version: 63.0a1
 * Build ID: 20180628220051

Comment 1

[YUKI "Piro" Hiroshi]

Please note that Chrome's selection behavior for shift-click is common on multiple GUI applications. For example: Windows Explorer (file selection), Microsoft Excel (cell selection), and Firefox itself (Places Organizer's row selection).