; Replace (non-)nil with (non-)@code{nil} in texinfo files

* doc/lispref/functions.texi:
* doc/lispref/keymaps.texi:
* doc/lispref/strings.texi:
* doc/misc/cl.texi:
* doc/misc/dbus.texi:
* doc/misc/eshell.texi:
* doc/misc/message.texi:
* doc/misc/ses.texi:
* doc/misc/vtable.texi: Replace (non-)nil with (non-)@code{nil}.

doc/lispref/functions.texi

@@ -2089,7 +2089,7 @@ code) obey the advice and other calls (from C code) do not.
 
 @defmac define-advice symbol (where lambda-list &optional name depth) &rest body
 This macro defines a piece of advice and adds it to the function named
-@var{symbol}.  If @var{name} is non-nil, the advice is named
+@var{symbol}.  If @var{name} is non-@code{nil}, the advice is named
 @code{@var{symbol}@@@var{name}} and installed with the name @var{name}; otherwise,
 the advice is anonymous.  See @code{advice-add} for explanation of
 other arguments.

doc/lispref/keymaps.texi

@@ -2603,10 +2603,10 @@ operates on menu data structures, so you should write it so it can
 safely be called at any time.
 
 @item :wrap @var{wrap-p}
-If @var{wrap-p} is non-nil inside a tool bar, the menu item is not
-displayed, but instead causes subsequent items to be displayed on a
-new line.  This is not supported when Emacs uses the GTK+ or Nextstep
-toolkits.
+If @var{wrap-p} is non-@code{nil} inside a tool bar, the menu item is
+not displayed, but instead causes subsequent items to be displayed on
+a new line.  This is not supported when Emacs uses the GTK+ or
+Nextstep toolkits.
 @end table
 
 @node Menu Separators

doc/lispref/strings.texi

@@ -1499,7 +1499,7 @@ case.
 The definition of a word is any sequence of consecutive characters that
 are assigned to the word constituent syntax class in the current syntax
 table (@pxref{Syntax Class Table}); if @code{case-symbols-as-words}
-is non-nil, characters assigned to the symbol constituent syntax
+is non-@code{nil}, characters assigned to the symbol constituent syntax
 class are also considered as word constituent.
 
 When @var{string-or-char} is a character, this function does the same

doc/misc/cl.texi

@@ -388,10 +388,10 @@ This function prints an ellipsis (``@dots{}'') to @var{stream} (see
 above).  When @var{stream} is a buffer, the ellipsis will be given the
 @code{cl-print-ellipsis} text property.  The value of the text
 property will contain state (including @var{start}) in order to print
-the elided part of @var{object} later.  @var{start} should be nil if
-the whole @var{object} is being elided, otherwise it should be an
-index or other pointer into the internals of @var{object} which can be
-passed to `cl-print-object-contents' at a later time.
+the elided part of @var{object} later.  @var{start} should be
+@code{nil} if the whole @var{object} is being elided, otherwise it
+should be an index or other pointer into the internals of @var{object}
+which can be passed to `cl-print-object-contents' at a later time.
 @end defun
 
 @defvar cl-print-expand-ellipsis-function

doc/misc/dbus.texi

@@ -1420,7 +1420,7 @@ We are not an owner of the name @var{service}.
 @end table
 
 When @var{service} is not a known name but a unique name, the function
-returns nil.
+returns @code{nil}.
 @end defun
 
 When a name has been chosen, Emacs can offer its own methods, which

doc/misc/eshell.texi

@@ -1758,8 +1758,8 @@ shells, there are also many differences.  Don't let these similarities
 lull you into a false sense of familiarity.
 
 When using command form (@pxref{Invocation}), Eshell will ignore any
-leading nil values, so if @var{foo} is @code{nil}, @samp{$@var{foo}
-echo hello} is equivalent to @samp{echo hello}.
+leading @code{nil} values, so if @var{foo} is @code{nil},
+@samp{$@var{foo} echo hello} is equivalent to @samp{echo hello}.
 
 @table @code
 
@@ -2419,8 +2419,9 @@ an @code{eshell-generic-target} as described above).
 @defun eshell-function-target-create output-function &optional close-function
 Create a new virtual target for Eshell that repeatedly calls
 @var{output-function} with the redirected output, as described above.
-If @var{close-function} is non-nil, Eshell will call it when closing the
-target, passing non-@code{nil} if the redirected command succeeded.
+If @var{close-function} is non-@code{nil}, Eshell will call it when
+closing the target, passing non-@code{nil} if the redirected command
+succeeded.
 @end defun
 
 @node Pipelines

doc/misc/message.texi

@@ -2565,8 +2565,8 @@ into the message headers as the SMTP Method.  If @var{cond} is a
 function, it will be called in the message buffer without any
 arguments, and the corresponding @var{method} will be inserted into
 the message headers as the SMTP Method if the function returns a
-non-@code{nil} value; if @var{method} is nil, the value returned by
-the function @code{cond} is used instead.
+non-@code{nil} value; if @var{method} is @code{nil}, the value
+returned by the function @code{cond} is used instead.
 
 @end table
 

doc/misc/ses.texi

@@ -1060,9 +1060,10 @@ as a single argument, since you'll probably use it with @code{ses-range}.
 
 Special cell values:
 @itemize
-@item nil prints typically the same as "", but allows previous cell to spill over.
-@item '*skip* replaces nil when the previous cell actually does spill over;
-nothing is printed for it.
+@item @code{nil} prints typically the same as "", but allows previous
+cell to spill over.
+@item '*skip* replaces @code{nil} when the previous cell actually does
+spill over; nothing is printed for it.
 @item '*error* indicates that the formula signaled an error instead of
 producing a value: the print cell is filled with hash marks (#).
 @end itemize

doc/misc/vtable.texi

@@ -559,9 +559,9 @@ table.
 @defun vtable-insert-object table object &optional location before
 Insert @var{object} into @var{table}.  @var{location} should be an
 object in the table, the new object is inserted after this object, or
-before it if @var{before} is non-nil.  If @var{location} is @code{nil},
-@var{object} is appended to @var{table}, or prepended if @var{before} is
-non-@code{nil}.
+before it if @var{before} is non-@code{nil}.  If @var{location} is
+@code{nil}, @var{object} is appended to @var{table}, or prepended if
+@var{before} is non-@code{nil}.
 
 @var{location} can also be an integer, a zero-based index into the
 table.  In this case, @var{object} is inserted at that index.  If the