Blocks located above character should block "drops of rain" effect, but they dont

What I expected to happen was...:
Blocks located above character should block "drops of rain" effect

What actually happened was...:
Rain goes through blocks as there no obstacle

Steps to Reproduce:
1. Make it raining
2. Go stand under roof made of solid blocks
3. Rain penetrates roof (example in attachments)

probably this bug applies only to blocks placed before transition to version 15w50a