Trailing white space in branch name is not stripped

Observed OS X client - Version 2.3.1 (69)

As a dev I want to create branches in Sourcetree but am bad at typing occasionally so i add a space to end my branch name.

When i attempt to do this I get this message...

git -c diff.mnemonicprefix=false -c core.quotepath=false -c credential.helper=sourcetree branch "feature/1234-this-is-a-branch " 
fatal: 'feature/1234-this-is-a-branch ' is not a valid branch name.
Completed with errors, see above

Unless you know what the problem is, its not immediately obvious what is wrong.

I would expect the flow to run a standard whitespace trim/chomp on the input string to allow me to create the branch.