Suggested text from username field is copied into password field (Twitter)

[Alberto Mardegan]

For some reason this bug only occures when creating a Twitter account from Online Accounts: type something in the username field, make sure that the virtual keyboad proposes some suggestion, then tap on the password field *on top of the "password" placeholder text* (if you tap on a white area, the bug does not occur).

Expected result: the focus switches to the password field
Actual result: the focus switches to the password field and the text suggested by the VK is copied into the password field.

[Olivier Tilloy (osomon)]

We’ve done a bit of investigation on this one together with Alberto and Michael, and while we didn’t get to the bottom of it, it seems that what happens is the following:

 - this specific twitter login page implements placeholder text for the input fields in a custom manner, where it overlays a <span> element containing the placeholder text on top of the input box
 - when switching focus from the username field to the password field by tapping on the password field’s placeholder, the password field briefly gets focus and it seems the current preedit in the username field is being committed (to the password field), and almost instantly it looses focus, resulting in the OSK being dismissed
 - the above doesn’t happen if focus is switched to the password field by tapping somewhere outside the placeholder text