Prior to this commit, `ResourceTransformer` implementations would
resolve internal links to other resources: both relative and absolute
request paths.
For relative request paths, those transformers would call
`ResourceTransformerSupport.resolveUrlPath` with the resource path,
as provided in the original file. This can cause problems when a
`CachingResourceResolver` is configured in the resolver chain, because
this resolver is caching resources, deriving the cache key from the
given resource path — this can cause collisions for cases like this:
resources/
|--foo/
| |--foo.css (imports style.css)
| |--style.css
|--bar/
| |--bar.css (imports style.css)
| |--style.css
The first "style.css" resolved resource is then cached and will be given
to any request asking for "style.css".
To avoid those issues, this commit improves the `ResourceTransformer`
implementations to calculate the absolute request path before asking the
chain to resolve the resource URL, thus avoiding duplications.
The resource chain will be then asked to resolve "/foo/style/css" or
"/bar/style.css".
Issue: SPR-14597
679b661e19