2 files changed, 19 insertions, 11 deletions

diff --git a/src/minibuf.c b/src/minibuf.c
index b23e24c4bd9..a0025e22720 100644
--- a/src/minibuf.c
+++ b/src/minibuf.c
@@ -1052,20 +1052,21 @@ A user option, or customizable variable, is one for which
 }
 
 DEFUN ("read-buffer", Fread_buffer, Sread_buffer, 1, 4, 0,
-       doc: /* Read the name of a buffer and return as a string.
-Prompt with PROMPT.
-Optional second arg DEF is value to return if user enters an empty line.
+       doc: /* Read the name of a buffer and return it as a string.
+Prompt with PROMPT, which should be a string ending with a colon and a space.
+Provides completion on buffer names the user types.
+Optional second arg DEF is value to return if user enters an empty line,
+ instead of that empty string.
  If DEF is a list of default values, return its first element.
-Optional third arg REQUIRE-MATCH determines whether non-existing
- buffer names are allowed.  It has the same meaning as the
+Optional third arg REQUIRE-MATCH has the same meaning as the
  REQUIRE-MATCH argument of `completing-read'.
-The argument PROMPT should be a string ending with a colon and a space.
+Optional arg PREDICATE, if non-nil, is a function limiting the buffers that
+can be considered.  It will be called with each potential candidate, and
+should return non-nil to accept the candidate for completion, nil otherwise.
 If `read-buffer-completion-ignore-case' is non-nil, completion ignores
 case while reading the buffer name.
 If `read-buffer-function' is non-nil, this works by calling it as a
-function, instead of the usual behavior.
-Optional arg PREDICATE if non-nil is a function limiting the buffers that can
-be considered.  */)
+function, instead of the usual behavior.  */)
   (Lisp_Object prompt, Lisp_Object def, Lisp_Object require_match,
    Lisp_Object predicate)
 {
diff --git a/src/window.c b/src/window.c
index 85d7bcade94..be338c2af61 100644
--- a/src/window.c
+++ b/src/window.c
@@ -7481,7 +7481,9 @@ reserve for the left marginal area.  Optional third arg RIGHT-WIDTH
 does the same for the right marginal area.  A nil width parameter
 means no margin.
 
-Return t if any margin was actually changed and nil otherwise.  */)
+Leave margins unchanged if WINDOW is not large enough to accommodate
+margins of the desired width.  Return t if any margin was actually
+changed and nil otherwise.  */)
   (Lisp_Object window, Lisp_Object left_width, Lisp_Object right_width)
 {
   struct window *w = set_window_margins (decode_live_window (window),
@@ -7563,11 +7565,14 @@ the left fringe.  Optional third arg RIGHT-WIDTH specifies the right
 fringe width.  If a fringe width arg is nil, that means to use the
 frame's default fringe width.  Default fringe widths can be set with
 the command `set-fringe-style'.
+
 If optional fourth arg OUTSIDE-MARGINS is non-nil, draw the fringes
 outside of the display margins.  By default, fringes are drawn between
 display marginal areas and the text area.
 
-Return t if any fringe was actually changed and nil otherwise.  */)
+Leave fringes unchanged if WINDOW is not large enough to accommodate
+fringes of the desired width.  Return t if any fringe was actually
+changed and nil otherwise.  */)
   (Lisp_Object window, Lisp_Object left_width,
    Lisp_Object right_width, Lisp_Object outside_margins)
 {
@@ -7692,6 +7697,8 @@ horizontal scroll bar: bottom, nil, or t where nil means to not display
 a horizontal scroll bar on WINDOW and t means to use WINDOW frame's
 horizontal scroll bar type.
 
+If WINDOW is not large enough to accommodate a scroll bar of the
+desired dimension, leave the corresponding scroll bar unchanged.
 Return t if scroll bars were actually changed and nil otherwise.  */)
   (Lisp_Object window, Lisp_Object width, Lisp_Object vertical_type,
    Lisp_Object height, Lisp_Object horizontal_type)