1813976 - [CTW] Language not reported for images

Status: NEW

(Core :: Disability Access APIs, defect)

Description

[James Teh [:Jamie]]

STR (with the NVDA screen reader):

1. In NVDA menu -> Settings -> Preferences -> Speech:
   • Set the Synthesizer to eSpeak NG.
   • Enable Automatic language switching.
2. Open this test case:
   data:text/html,<img alt="123" lang="de" src="https://via.placeholder.com/10x10">
3. Press down arrow to read the line.
   • Expected: NVDA speaks "einhundertdreiundzwanzig" (123 in German).
   • Actual: NVDA speaks "one hundred twenty three" in English.

In bug 1757127, I implemented support for Accessible::Language using the text atributes cache. However, images aren't HyperTextAccessibles, so they don't have text attributes. We'll need special handling for this. We can either:

1. Cache language in the main cache for this case.
2. Create a text attributes cache with just this one attribute. While a bit wasteful, it does make the retrieval code simpler.

Either way, we'll need a different code path in BundleFieldsForCache.