Godot: Condition ' name == "" ' is true when new name contains only unallowed characters

[qarmin]

Godot version:
3.1 0b0dba3

OS/device including version:
Windows 10

Issue description:
When I try to change name node to empty name "" - then popup "No name provided" appear
When I try to change name node to "nodename//" then node change name to "nodename" and show popup "Invalid node name ..."
But when I try to change name of node to name which contains only unallowed characters, then popup "Invalid node name ..." is shown and also this error:

scene/main/node.cpp:930 - Condition ' name == "" ' is true.

[akien-mga]

You're a really good QA engineer of the "ordering -1 beers" kind :D

QA Engineer walks into a bar. Orders a beer. Orders 0 beers. Orders 999999999 beers. Orders a lizard. Orders -1 beers. Orders a sfdeljknesv.

[yehjaemin]

If no one else is interested, could I get assigned to this?