Bug 222896 – Be more restrictive about when canvas2d is allowed to update style

• Component: New Bugs
• Status: RESOLVED FIXED

[Myles C. Maxfield]

Be more restrictive about when canvas2d is allowed to update style

[Myles C. Maxfield]

Created attachment 422542 [details]
Patch

[Myles C. Maxfield]

Comment on attachment 422542 [details]
Patch

I shouldn't move toTextDirection() before the RAII classes.

[Radar WebKit Bug Importer]

<rdar://problem/75416260>

[Myles C. Maxfield]

Created attachment 423304 [details]
Patch

[Ryosuke Niwa]

Comment on attachment 423304 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=423304&action=review

> Source/WebCore/html/canvas/CanvasRenderingContext2D.cpp:121
> +    WidgetHierarchyUpdatesSuspensionScope suspendWidgetHierarchyUpdates;
> +    ScriptDisallowedScope::InMainThread scriptDisallowedScope;
> +    Style::PostResolutionCallbackDisabler callbackDisabler(canvas().document());

We don't need WidgetHierarchyUpdatesSuspensionScope or PostResolutionCallbackDisabler.
Just ScriptDisallowedScope::InMainThread is enough.

> Source/WebCore/html/canvas/CanvasRenderingContext2D.cpp:163
> -    auto* style = (computedStyle || direction == Direction::Inherit) ? canvas().computedStyle() : nullptr;
> +    auto* style = (computedStyle || direction == Direction::Inherit) ? canvas().existingComputedStyle() : nullptr;

Maybe get rid of the unnecessary parenthesis here?

> Source/WebCore/html/canvas/CanvasRenderingContext2D.cpp:201
> +    WidgetHierarchyUpdatesSuspensionScope suspendWidgetHierarchyUpdates;
> +    ScriptDisallowedScope::InMainThread scriptDisallowedScope;
> +    Style::PostResolutionCallbackDisabler callbackDisabler(canvas().document());

Ditto. We just need ScriptDisallowedScope::InMainThread here.

> Source/WebCore/html/canvas/CanvasRenderingContext2D.cpp:-195
> -    auto& canvas = downcast<HTMLCanvasElement>(canvasBase());
> -    canvas.document().updateStyleIfNeeded();

Let's also add ScriptDisallowedScope::InMainThread here?

> Source/WebCore/html/canvas/CanvasRenderingContext2D.cpp:234
> +    WidgetHierarchyUpdatesSuspensionScope suspendWidgetHierarchyUpdates;
> +    ScriptDisallowedScope::InMainThread scriptDisallowedScope;
> +    Style::PostResolutionCallbackDisabler callbackDisabler(canvas().document());

Ditto. We just need ScriptDisallowedScope::InMainThread.

[Myles C. Maxfield]

Created attachment 423378 [details]
Patch for committing

[Myles C. Maxfield]

Committed r274531 (235382@main): <https://commits.webkit.org/235382@main>