Prevent Helm from opening in a new frame

Question

I recently updated Helm from MELPA to version helm-20180305.1056 and helm-core-20180306.2241. Now sometimes when I use Helm it opens in a new frame. I think this happens when I have 2x1 or 2x2 window configuration and point is currently in the part of the frame where there is one window above another window:

+----+----+          +----+----+
|    |    |          |    |    |
+----+    |    or    +----+----+
|    |    |          |    |    |
+----+----+          +----+----+

I do not experience this with only one horizontal or vertical split like below:

+------------+          +----+----+
|            |          |    |    |
+------------+    or    |    |    |
|            |          |    |    |
+------------+          +----+----+

My Helm config is;

(use-package helm
  :ensure t
  :diminish
  :config
  (use-package helm-config)
  (helm-mode 1)
  (helm-autoresize-mode 1)
  (setq helm-split-window-in-side-p t)
  :bind
  (("M-x" . helm-M-x)
   ("C-x C-f" . helm-find-files)
   ("C-x C-b" . helm-buffers-list)
   ("M-s o" . helm-occur)
   ("M-s i" . helm-imenu)
   ("M-s I" . helm-imenu-in-all-buffers)))

How do I prevent Helm from ever opening in a new frame and instead always use the current window?

Answer 1

I search through the commits for helm version 2.8.8 and found the cause for the new behaviour. This commit introduces the customizable variable helm-use-frame-when-more-than-two-windows. Set to true (the default) makes helm always use a new frame when there already is more than two windows. Set to nil helm will use a window instead, which is what I want.