The spec currently says

Queue timeline steps:

1. Let passingFragments be non-zero if any fragment samples passed all per-fragment tests since the corresponding beginOcclusionQuery() command was executed.

2. Write passingFragments into this.[[occlusion_query_set]] at index renderState.[[occlusionQueryIndex]].

• it doesn't specify what passingFragments is if no samples passed. It only says if any samples passed then passingFragments is non-zero.

  should it say passingFragments is zero if no samples passed or is it good enough that it's maybe implied?

• it doesn't specify what happens if there is no draw between beginOcclusionQuery and endOcclusionQuery.

  should it say anything here? For example

  if no draw then passingFramnents is:

  • undefined? (up to implementation)
  • untouched? (previous value in query set remains as is)
  • zero?