1234031 - Textarea may be scrollable (overflowed) without visible scrollbar

Status: NEW

(Core :: Layout: Text and Fonts, defect)

Description

[arni2033]

Attachment: testcase 1 - textarea isn't autoscrollable as well as the page itself.htm

>>>   My Info:   Win7_64, Nightly 46, 32bit, ID 20151219030215
STR:
1. Open attached "testcase 1"
2. Move mouse over the center of <textarea>, click middle mouse button to display "autoscroll circle"
3. Move mouse toward the bottom of the page to start autoscrolling

Result:       
 Textarea scrolls by 1px and then nothing happen.

Expectations: 
 Textarea should display scrollbar to indicate that there's overflow.
 Because current behavior is very confuzing.

Note:
 I think this is caused by weird line-height, just like bug 1208412. I faced both of them on Bugzilla

Comment 1

[arni2033]

I'm still able to reproduce this with HWA disabled if I set 
"height: 263px;  line-height: 15.5px;"  or only  "height: 264.5px;"  to textarea.