1353423 - Bootstrap 4 alpha 6 and FF Nighlty: select.form-control inside a div.input-group closes itself when being selected

Status: RESOLVED FIXED

(Core :: CSS Parsing and Computation, defect, P3)

Description

[mariano]

Attachment: ff-nighlty-select-display-flex-bug.mp4

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:55.0) Gecko/20100101 Firefox/55.0
Build ID: 20170404100210

Steps to reproduce:

open this on firefox nightly: https://thimbleprojects.org/marianoguerra/245409/

click on the first select, for me it closes itself



Actual results:

when clicking on the first select it doesn't stay open


Expected results:

should stay open, like the other ones

Comment 1

[Vlad Bacia-Mociran [:VladB]]

User Agent: Mozilla/5.0 (Windows NT 6.3; Win64; x64; rv:55.0) Gecko/20100101 Firefox/55.0


I have tested your issue on latest Nightly build (Buid ID: 20170406030206) and managed to reproduce it. I did a regression range using mozregression in order to find what broke this behavior because on Firefox latest release this issue is not reproducible. 

INFO: Narrowed inbound regression window from [7c9940c5, bd7af7e5] (3 revisions) to [620f5ed5, bd7af7e5] (2 revisions) (~1 steps left)
INFO: Oh noes, no (more) inbound revisions :(
INFO: Last good revision: 620f5ed5c91ec42874c6b725d8caddb713bbe022
INFO: First bad revision: bd7af7e530068aeebf1c357bfed8e8d4c43e2d05
INFO: Pushlog:
https://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?fromchange=620f5ed5c91ec42874c6b725d8caddb713bbe022&tochange=bd7af7e530068aeebf1c357bfed8e8d4c43e2d05

Bug 1302054 or Bug 1301258 broke this.
@Cameron, can you please take a look at this? Thank you.

Comment 2

[Cameron McCormack (:heycam)]

Thanks, I can reproduce this.

Comment 3

[Cameron McCormack (:heycam)]

Attachment: test

Here's a minimized test.

Comment 4

[Cameron McCormack (:heycam)]

The problem seems to be that in bug 997709, we added a special case to prevent ::-moz-display-comboboxcontrol-frame anonymous boxes from having parent-based style fixup applied to them, since their mContent is the <select>, and we don't want the nsComboboxDisplayFrame to be blockified.  But we only handle this during the initial styling of the nsComboboxDisplayFrame, so if we restyle it later (and specifically, restyle it with ReparentStyleContext), it can end up switching display from inline to block, generating an nsChangeHint_ReconstructFrame, which prevents the popup from showing.  Bug 1302054 caused us to actually compare the old and new Display structs, which uncovered this issue.

With the patch I'll attach soon, there is still a problem with the <select> dropdown not showing the first time it's clicked.  I'll file a followup for that.

Comment 5

[Cameron McCormack (:heycam)]

Pretty sure this got fixed by bug 1376406.