1366427 - stylo: Backdrop pseudo should not inherit.

Status: RESOLVED FIXED

(Core :: CSS Parsing and Computation, defect)

Description

[Emilio Cobos Álvarez (:emilio)]

Right now ServoStyleSet ignores the aParentStyleContext argument arriving to ResolvePseudoElementStyle, assuming the pseudo should inherit from the element.

This is completely wrong for ::backdrop, which should not inherit from anything.

I'm adding restyling for ::backdrop in bug 1364871. I plan to fix the behavior of ::backdrop here.

Comment 1

[Emilio Cobos Álvarez (:emilio)]

Attachment: Bug 1366427: Make backdrop not inherit from the parent element.

Review commit: https://reviewboard.mozilla.org/r/141268/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/141268/

Comment 2

[Cameron McCormack (:heycam)]

Comment on attachment 8869693 [details]
Bug 1366427: Make backdrop not inherit from the parent element.

https://reviewboard.mozilla.org/r/141268/#review144900

::: servo/ports/geckolib/glue.rs:1185
(Diff revision 1)
> -            let base = styles.primary.values();
> +            let base = if pseudo.inherits_from_parent() {
> +                styles.primary.values()
> +            } else {
> +                d.default_computed_values()
> +            };

Since the usual behaviour is to inherit from the parent, I think it might make sense to invert the function here, and have it be "inherits_from_default_styles" or something.  Reading this code here, otherwise, it's not obvious why if inherits_from_parent() is false, that we should use the default computed values.

Alternatively you could use an enum, but I think inheriting from the parent seems obvious enough to not need to be explicitly written.

Comment 3

[Emilio Cobos Álvarez (:emilio)]

Comment on attachment 8869693 [details]
Bug 1366427: Make backdrop not inherit from the parent element.

https://reviewboard.mozilla.org/r/141268/#review144900

> Since the usual behaviour is to inherit from the parent, I think it might make sense to invert the function here, and have it be "inherits_from_default_styles" or something.  Reading this code here, otherwise, it's not obvious why if inherits_from_parent() is false, that we should use the default computed values.
> 
> Alternatively you could use an enum, but I think inheriting from the parent seems obvious enough to not need to be explicitly written.

Sounds good, will do :)

Comment 4

[Bobby Holley (:bholley)]

Emilio, did this land?

Comment 5

[Emilio Cobos Álvarez (:emilio)]

Yes, https://hg.mozilla.org/mozilla-central/rev/73f9c356e367