RFR: 8351264: Some images don't load with WebKit 620.1

[Kevin Rushforth]

On Mon, 17 Mar 2025 13:46:06 GMT, Jose Pereda <jpereda at openjdk.org> wrote:

>> Issue: Some images don't load with WebKit 620.1
>> 
>> WebKit Image Decoding Failure Due to Unintended WebP Format Delivery
>> WebKit encounters image decoding failures when certain servers respond with WebP images instead of the intended JPEG or PNG format. This issue arises due to WebKit's Accept header configuration, which prioritises WebP by default. Consequently, incomplete or malformed WebP data results in decoding errors.
>> 
>> Solution:
>> Keep the image rendering features and supported formats as webkit 619.1 , and accordingly
>> update the Accept header to prioritize JPEG/PNG over WebP unless WebP decoding is confirmed stable.
>
> modules/javafx.web/src/main/native/Source/WebCore/loader/cache/CachedResourceRequest.cpp line 151:
> 
>> 149:         StringBuilder builder;
>> 150: // Java platform failing to decode webp image data already disabled in 619.1
>> 151: #if (HAVE(WEBP) || USE(WEBP)) && !PLATFORM(JAVA)
> 
> I see that 619.1 indeed had:
> 
> #if HAVE(WEBP) || USE(WEBP)
>          builder.append("image/webp,"_s);
> #endif
> 
> I wonder why the condition `!PLATFORM(JAVA)` is also required now?

Likely those two flags are now defined (in 620.1), but weren't defined in 619.1. It is therefore safer to add the `!PLATFORM(JAVA)` and in any case any time we modify code from upstream, we should qualify it with a `PLATFORM(JAVA)` check.

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PR Review Comment: https://git.openjdk.org/jfx/pull/1738#discussion_r1998974216