diff --git a/README b/README
index 0b0d3a3eac6..18b5ff89273 100644
--- a/README
+++ b/README
@@ -72,6 +72,8 @@ There are several subdirectories:
 'lib'       holds source code for libraries used by Emacs and its utilities
 'lib-src'   holds the source code for some utility programs for use by or
             with Emacs, like movemail and etags.
+'lwlib'     holds the sources of the Lucid Widget Library used on X.
+'oldXMenu'  source files from X11R2 XMenu library, used in non-toolkit builds.
 'etc'       holds miscellaneous architecture-independent data files Emacs
             uses, like the tutorial text and tool bar images.
             The contents of the 'lisp', 'leim', 'info', and 'doc'
@@ -89,6 +91,10 @@ There are several subdirectories:
             Nextstep port of Emacs, for GNUstep and macOS Cocoa.
 'nt'        holds code and documentation for building Emacs on MS-Windows.
 'test'      holds tests for various aspects of Emacs's functionality.
+'modules'   holds the modhelp.py helper script.
+'admin'     holds files used by Emacs developers, and Unicode data files.
+'build-aux' holds auxiliary files used during the build.
+'m4'        holds Autoconf macros used for generating the configure script.
 
    Building Emacs on non-Posix platforms requires tools that aren't part
 of the standard distribution of the OS.  The platform-specific README
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
diff --git a/lisp/erc/erc.el b/lisp/erc/erc.el
index eee79464a9a..bda8dc1e714 100644
--- a/lisp/erc/erc.el
+++ b/lisp/erc/erc.el
@@ -1850,6 +1850,7 @@ removed from the list will be disabled."
   :get (lambda (sym)
          ;; replace outdated names with their newer equivalents
          (erc-migrate-modules (symbol-value sym)))
+  :initialize 'custom-initialize-default
   :set (lambda (sym val)
          ;; disable modules which have just been removed
          (when (and (boundp 'erc-modules) erc-modules val)
diff --git a/lisp/gnus/gnus-group.el b/lisp/gnus/gnus-group.el
index 63e59e94e2e..e9819191193 100644
--- a/lisp/gnus/gnus-group.el
+++ b/lisp/gnus/gnus-group.el
@@ -628,7 +628,7 @@ simple manner."
   "\M-e" gnus-group-edit-group-method
   "^" gnus-group-enter-server-mode
   [mouse-2] gnus-mouse-pick-group
-  [follow-link] 'mouse-face
+  [follow-link] mouse-face
   "<" beginning-of-buffer
   ">" end-of-buffer
   "\C-c\C-b" gnus-bug
diff --git a/src/xterm.c b/src/xterm.c
index 1b45cf1b0b7..e42216886bc 100644
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -3517,13 +3517,13 @@ x_draw_underwave (struct glyph_string *s)
 
   x_get_scale_factor (s->display, &scale_x, &scale_y);
 
-  int wave_height = 3 * scale_y, wave_length = 2 * scale_x, thickness = scale_y;
+  int wave_height = 3 * scale_y, wave_length = 2 * scale_x;
 
 #ifdef USE_CAIRO
   x_draw_horizontal_wave (s->f, s->gc, s->x, s->ybase - wave_height + 3,
 			  s->width, wave_height, wave_length);
 #else  /* not USE_CAIRO */
-  int dx, dy, x0, y0, width, x1, y1, x2, y2, xmax;
+  int dx, dy, x0, y0, width, x1, y1, x2, y2, xmax, thickness = scale_y;;
   bool odd;
   XRectangle wave_clip, string_clip, final_clip;