Merge from origin/emacs-26

5381c70b7a In windows.texi mention special splitting behavior of side...
46d62b9f36 * lisp/gnus/gnus-group.el (gnus-group-mode-map): Bind [fol...
1ef1dbdbc5 Avoid compilation warning in xterm.c
5cf3c26f2d * README: Document all the top-level directories.  (Bug#29...
e9ea2065a8 Don't enable erc modules on simply loading erc.el

1 files changed, 4 insertions, 1 deletions

diff --git a/doc/lispref/windows.texi b/doc/lispref/windows.texi
index e1eac457179..08ed092c48c 100644
--- a/doc/lispref/windows.texi
+++ b/doc/lispref/windows.texi
@@ -1109,7 +1109,10 @@ the size of @var{window} is not preserved.
 @cindex window splitting
 
 This section describes functions for creating a new window by
-@dfn{splitting} an existing one.
+@dfn{splitting} an existing one.  Note that some windows are special in
+the sense that these functions may fail to split them as described here.
+Examples of such windows are side windows (@pxref{Side Windows}) and
+atomic windows (@pxref{Atomic Windows}).
 
 @defun split-window &optional window size side pixelwise
 This function creates a new live window next to the window