I'm playing in the latest snapshot (18w47b) and I've made a few banners that I've named in an anvil. I've placed them down and right-clicked them with a map, and while the banner does show up on the map, the name does not. I've tried with both black and white banners and the problem remains. The correct colors show up but the names of the banners do not.
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It is fixed for banners placed on the ground, but it does still affect banners placed on the wall in 18w49a! Please reopen!

Exactement: bannières murales ont pas de nom sur la carte en 18w49a, mais même pour les bannières placées sur le dessus d'un bloc, la carte doit se tenir dans la main gauche en cliquant droit avec la main droite vide pour que le nom apparaît sur la carte . Un clic droit avec la carte dans la main place le marqueur sur la carte, mais sans le nom.
Updated the title to more accurately reflect the real issue. This can be observed by doing the following:
1. Obtain and name a banner
2. Place it in the world
3.
/data get block X Y Z
→ ❌ There is no
CustomName
Adding the
CustomName
with commands will cause it to appear on the map as expected, and copy to the item when broken. The only issue here is copying item -> block.