939489 - CustomizeMode should null-check documentElement._lightweightTheme

Status: RESOLVED FIXED

(Firefox :: Toolbars and Customization, defect)

Description

[Blair McBride [:Unfocused] (UNAVAILABLE)]

Seems documentElement._lightweightTheme can be null, if an add-on sets lightweightthemes=false on the <window>. Easy fix to avoid breakage is to just add a null-check when we try to use this in CustomizeMode.jsm.

Comment 1

[Blair McBride [:Unfocused] (UNAVAILABLE)]

Attachment: Patch v1

Comment 2

[Mike Conley (:mconley) (:⚙️)]

Comment on attachment 833397 [details] [diff] [review]
Patch v1

Review of attachment 833397 [details] [diff] [review]:
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Nice and defensive. Thanks Blair!

Comment 3

[:Gijs (he/him)]

I wonder if we should make the catch blocks in customization enter/exit display some kind of message if something borked when entering/exiting. Pretty bad UI breakage if any of it breaks, tbh.

Comment 4

[Blair McBride [:Unfocused] (UNAVAILABLE)]

(In reply to :Gijs Kruitbosch from comment #3)
> I wonder if we should make the catch blocks in customization enter/exit
> display some kind of message if something borked when entering/exiting.
> Pretty bad UI breakage if any of it breaks, tbh.

Possibly... but that would also mean we're *far* less likely to found out about issues, which IMO is more important at this stage.

Comment 5

[Blair McBride [:Unfocused] (UNAVAILABLE)]

https://hg.mozilla.org/projects/ux/rev/9f997c45050c

Comment 6

[:Gijs (he/him)]

(In reply to Blair McBride [:Unfocused] from comment #4)
> (In reply to :Gijs Kruitbosch from comment #3)
> > I wonder if we should make the catch blocks in customization enter/exit
> > display some kind of message if something borked when entering/exiting.
> > Pretty bad UI breakage if any of it breaks, tbh.
> 
> Possibly... but that would also mean we're *far* less likely to found out
> about issues, which IMO is more important at this stage.

To be clear, I would put something like "Uh-oh, opening customization mode failed with the following error: ... please report this here: [custom bugzilla link]." but I see your point, I guess.

Comment 7

[:Gijs (he/him)]

https://hg.mozilla.org/mozilla-central/rev/9f997c45050c