So I was playing with the banners and I wanted to move a banner. It wasn't in my inventory and I was in creative mode, and I didn't want to re-create the banner. I middle clicked the banner and then it gave me a black banner instead of the banner in front of me.
Steps to Reproduce:
1. place any banner down in creative
2. middle click the banner or whatever button you use for pick block
3. you get a black banner
Picture: what happened after i middle clicked
This issue has been reported already. It has been linked to the original bugreport.
Please search before reporting any bugs, as it's likely that one exists already.