diff --git a/doc/lispref/control.texi b/doc/lispref/control.texi
index f9f3389c398..06bf51d8072 100644
--- a/doc/lispref/control.texi
+++ b/doc/lispref/control.texi
@@ -350,7 +350,8 @@ kinds of multiple conditional constructs.
 This function tests for the falsehood of @var{condition}.  It returns
 @code{t} if @var{condition} is @code{nil}, and @code{nil} otherwise.
 The function @code{not} is identical to @code{null}, and we recommend
-using the name @code{null} if you are testing for an empty list.
+using the name @code{null} if you are testing for an empty list or
+@code{nil} value.
 @end defun
 
 @defspec and conditions@dots{}
diff --git a/doc/lispref/lists.texi b/doc/lispref/lists.texi
index 1409e51c0d4..14862bdfc2a 100644
--- a/doc/lispref/lists.texi
+++ b/doc/lispref/lists.texi
@@ -143,9 +143,9 @@ This function is the opposite of @code{listp}: it returns @code{t} if
 @defun null object
 This function returns @code{t} if @var{object} is @code{nil}, and
 returns @code{nil} otherwise.  This function is identical to @code{not},
-but as a matter of clarity we use @code{null} when @var{object} is
-considered a list and @code{not} when it is considered a truth value
-(see @code{not} in @ref{Combining Conditions}).
+but as a matter of clarity we use @code{not} when @var{object} is
+considered a truth value (see @code{not} in @ref{Combining
+Conditions}) and @code{null} otherwise.
 
 @example
 @group
diff --git a/doc/misc/calc.texi b/doc/misc/calc.texi
index ac2ac5a0f91..f7b7e277b58 100644
--- a/doc/misc/calc.texi
+++ b/doc/misc/calc.texi
@@ -31468,6 +31468,7 @@ newline so that mode annotations will appear on lines by themselves.
 @node Programming
 @chapter Programming
 
+@cindex Programming Calc
 @noindent
 There are several ways to ``program'' the Emacs Calculator, depending
 on the nature of the problem you need to solve.
@@ -31596,7 +31597,7 @@ following sections.
 
 @noindent
 @kindex X
-@cindex Programming with keyboard macros
+@cindex Programming Calc, with keyboard macros
 @cindex Keyboard macros
 The easiest way to ``program'' the Emacs Calculator is to use standard
 keyboard macros.  Press @w{@kbd{C-x (}} to begin recording a macro.  From
@@ -31997,7 +31998,7 @@ The @kbd{m m} command saves the last invocation macro defined by
 @noindent
 @kindex Z F
 @pindex calc-user-define-formula
-@cindex Programming with algebraic formulas
+@cindex Programming Calc, with algebraic formulas
 Another way to create a new Calculator command uses algebraic formulas.
 The @kbd{Z F} (@code{calc-user-define-formula}) command stores the
 formula at the top of the stack as the definition for a key.  This
@@ -32106,6 +32107,7 @@ in symbolic form without ever activating the @code{deriv} function.  Press
 @node Lisp Definitions
 @section Programming with Lisp
 
+@section Programming Calc, with Lisp
 @noindent
 The Calculator can be programmed quite extensively in Lisp.  All you
 do is write a normal Lisp function definition, but with @code{defmath}
@@ -32851,6 +32853,7 @@ a large argument, a simpler program like the first one shown is fine.
 @node Calling Calc from Your Programs
 @subsection Calling Calc from Your Lisp Programs
 
+@cindex Calling Calc from Lisp
 @noindent
 A later section (@pxref{Internals}) gives a full description of
 Calc's internal Lisp functions.  It's not hard to call Calc from
diff --git a/lisp/dnd.el b/lisp/dnd.el
index 1fc1ab45b84..411f0d5774c 100644
--- a/lisp/dnd.el
+++ b/lisp/dnd.el
@@ -151,8 +151,13 @@ Windows."
                 (with-selected-window window
                   (scroll-down 1))))))))
       (when dnd-indicate-insertion-point
-        (ignore-errors
-          (goto-char (posn-point posn)))))))
+        (let ((pos (posn-point posn)))
+          ;; We avoid errors here, since on some systems this runs
+          ;; when waiting_for_input is non-zero, and that aborts on
+          ;; error.
+          (if (and pos (<= (point-min) pos (point-max)))
+              (goto-char pos)
+            pos))))))
 
 (defun dnd-handle-one-url (window action url)
   "Handle one dropped url by calling the appropriate handler.