git-cl and pop-up window with text editor - what is it for?

[Frédéric Bron]

Hi,
When I use git-cl, a pop-up window opens with vim. I typed a message
but couldn't find it anywhere in the issue tracker nor in codereview.
Also, I noticed that git-cl was continuing in the initial terminal
while I was typing the message in the popup window.
What is this message window for? Is it normal behaviour?
Frédéric

PS: my .gitconfig says editor = vim