1665477 - When dragging a pinned tab to a window where tabs are overflowing, the "it'll go here" marker shows up at the wrong spot

Status: NEW

(Firefox :: Tabbed Browser, defect, P3)

Description

[Daniel Holbert [:dholbert]]

Attachment: screencast

STR:

1. Open two Firefox windows, with pinned tabs in each.
2. In the first window, create enough non-pinned tabs that there's overflow and < / > buttons at the edge of the tab strip.
3. Drag a pinned tab from the second window to the first window, and try to place it at the far right edge of the pinned-tab region. (Drag it over the space between the last pinned tab and the < button.)

ACTUAL RESULTS:
The "it'll go here" cursor/marker shows up on the right side of the < button (in the normal-tabs area). But that's not where it actually goes, when you drop it! It really ends up on the left side of the < button (where I dragged it).

EXPECTED RESULTS:
The "it'll go here" cursor/marker should show up on the left side of the < button, to show the spot where it's going to actually end up.

See attached screencast. The bug is visible after 0:06.

Comment 1

[Daniel Holbert [:dholbert]]

Attachment: screenshot showing the marker appearing at wrong position (on opposite side of "<" icon, from where I'm dropping the tab)