1327901 - Text inside contenteditable field twitches vertically by 1px when I focus it

Status: NEW

(Core :: Layout: Text and Fonts, defect, P4)

Description

[arni2033]

>>>   My Info:   Win7_64, Nightly 49, 32bit, ID 20160526082509
STR_1:
1. Download attachment 8757114 [details] (from bug 1276122)
   Extract it into a folder with a short full name
2. Open "2016.04.18 22-35-57 �������.htm" in Firefox
3. Type "asdf\nzxcv" inside the entry field (element with selector "#im_editable7777777")
4. Enter responsive design mode (Ctrl+Shift+M), set dimensions to 1280x919, reload the page (F5)
5. {Click inside the entry field to focus it, then click outside of the field}  several times

AR:
 When the field is focused, line "zxcv" has one position
 when the field isn't focused, line "zxcv" teleports 1px below its original position
 I.e. the 2nd line in entry field twitches up/down by 1px during Step 5
ER:
 No twitching in Step 5
 
I added stylesheet `*{cursor:default!important;}` to record the screencast. More results:
 dimensions set in Step 4     | result of Step 5
----------------------------------------------------------------
   1280x919                   |   Second line twitches by 1px
   1280x920                   |   no twitching
   1280x921                   |   First line twitches by 1px
   1280x922                   |   no twitching
   1280x923                   |   no twitching
   1280x924                   |   Second line twitches by 1px
   1280x925                   |   no twitching
   1280x926                   |   First line twitches by 1px

Comment 1

[arni2033]

Attachment: screencast 1 - Text twitches up and down by 1px.webm