Bug 44430 – [Qt] WebCore crashes from the web process.

• Component: Platform
• Status: RESOLVED INVALID

[Balazs Kelemen]

In situations where we want to cast a client class to it's qt version (for example a FrameLoaderClient to a FrameLoaderClientQt) are crashing in the web process of webkit2 since the type of the clients are differs. Currently I do not see a better fix for this then doing some hand written rtti (because we should not rely on rtti support) and check the type of those clients. In the future we should eliminate the layering violations and/or introducing better abstractions to deal with the duality of the API layers but for now the webkit2 project needs a working implementation in the trunk.

[Kenneth Rohde Christiansen]

We should just fix the layering violations instead and never do casts like these :)

[Balazs Kelemen]

Created attachment 65236 [details]
proposed patch

[Kenneth Rohde Christiansen]

Comment on attachment 65236 [details]
proposed patch

First of all, each of these should be separate patches!

Secondly, there is another patch from Jesus and Diego fixing some of these issues, but it is not 100% ready yet.

Thirdly, this is too hacky and it is better to spend the time on fixing this properly by removing the layering violations or helping Jesus and Diego finish their patch.

[Balazs Kelemen]

(In reply to comment #3)
> (From update of attachment 65236 [details])
> First of all, each of these should be separate patches!
> 
> Secondly, there is another patch from Jesus and Diego fixing some of these issues, but it is not 100% ready yet.

That patch does not covers the PluginData problem. Do you think we should introduce a PluginDataContext there?

> 
> Thirdly, this is too hacky and it is better to spend the time on fixing this properly by removing the layering violations or helping Jesus and Diego finish their patch.

I can degrease the hackiness via using dynamic_cast but as I know rtti should be avoided in WebKit (and also in Qt maybe).
You should take in account that even if we could solve the layering violations (that is materialized now in the form of casting and abstract client class to the concrete qt one), we won't have the fancy API-s of WebKit in WebKit2 so we should provide a default behavior.
I would ask you to help me by discussing what design we should follow to solve these problems. Creating *Context abstractions? Using PlatformStrategies somehow? Merging API of WebKit and WebKit2?