fish: fix git prompt not showing staged changes if there's no commit

user/fish/fish_prompt.fish

@@ -103,9 +103,8 @@ function fish_git_prompt
        _fish_prompt_warn "init"
     end
 
-    git rev-parse HEAD -- &>/dev/null
-    or return
-
+    # if we have at least one commit
+    if git rev-parse HEAD -- &>/dev/null
         # print a "↑" if ahead of origin
         test 0 -ne (git log --oneline "$git_remote_branch"..HEAD -- | wc -l)
         and set -f _git_sync_ahead '↑'
@@ -127,6 +126,7 @@ function fish_git_prompt
             _fish_prompt_normal '↻'
             _fish_prompt_warn $git_log_unpushed[1]
         end
+    end
 
     ############################################################
     # Right side represents WorkTree/Staged