; Fix documentation of last change

* lisp/minibuffer.el (completion-category-overrides): Doc fix.

* doc/emacs/mini.texi (Completion Options): Update documentation
of 'completions-sort'.
* doc/lispref/minibuf.texi (Completion Variables): Fox wording.
Add a cross-reference to where 'completions-sort' is documented.

doc/emacs/mini.texi

@@ -709,7 +709,9 @@ will use just one column.
   The @code{completions-sort} user option controls the order in which
 the completions are sorted in the @samp{*Completions*} buffer.  The
 default is @code{alphabetical}, which sorts in alphabetical order.
-The value @code{nil} disables sorting.  The value can also be a
+The value @code{nil} disables sorting; the value @code{historical}
+sorts alphabetically first, and then rearranges according to the order
+of the candidates in the minibuffer history.  The value can also be a
 function, which will be called with the list of completions, and
 should return the list in the desired order.
 

doc/lispref/minibuf.texi

@@ -1880,10 +1880,12 @@ The value should be a value for @code{completion-cycle-threshold}
 category.
 
 @item display-sort-function
-The possible values are: @code{nil} that means to use either the sorting
-function from metadata or if it's nil then fall back to @code{completions-sort};
-@code{identity} that means to not use any sorting to keep the original order;
-and other values are the same as in @code{completions-sort}.
+The possible values are: @code{nil}, which means to use either the
+sorting function from metadata or if that is @code{nil}, fall back to
+@code{completions-sort}; @code{identity}, which means not to sort at
+all, leaving the original order; or any other value out of those used
+in @code{completions-sort} (@pxref{Completion Options,,, emacs, The
+GNU Emacs Manual}).
 @end table
 
 @noindent

lisp/minibuffer.el

@@ -1155,10 +1155,10 @@ Each override has the shape (CATEGORY . ALIST) where ALIST is
 an association list that can specify properties such as:
 - `styles': the list of `completion-styles' to use for that category.
 - `cycle': the `completion-cycle-threshold' to use for that category.
-- `display-sort-function': where `nil' means to use either the sorting
-function from metadata or if it's nil then fall back to `completions-sort';
-`identity' means to not use any sorting to keep the original order;
-and other values are the same as in `completions-sort'.
+- `display-sort-function': nil means to use either the sorting
+function from metadata, or if that is nil, fall back to `completions-sort';
+`identity' disables sorting and keeps the original order; and other
+possible values are the same as in `completions-sort'.
 
 Categories are symbols such as `buffer' and `file', used when
 completing buffer and file names, respectively.