Merge from origin/emacs-27

0a3731feef Make memq etc. examples more like they were
ed25282b82 Document effect of 'search-upper-case' on replacement comm...
5a5d8a8ec0 * lisp/desktop.el (desktop-save): Doc fix.  (Bug#41007)

doc/emacs/search.texi

@@ -1324,10 +1324,14 @@ case-sensitive.  Thus, searching for @samp{Foo} does not find
 @samp{foo} or @samp{FOO}.  This applies to regular expression search
 as well as to literal string search.  The effect ceases if you delete
 the upper-case letter from the search string.  The variable
-@code{search-upper-case} controls this: if it is non-@code{nil} (the
-default), an upper-case character in the search string makes the
-search case-sensitive; setting it to @code{nil} disables this effect
-of upper-case characters.
+@code{search-upper-case} controls this: if it is non-@code{nil}, an
+upper-case character in the search string makes the search
+case-sensitive; setting it to @code{nil} disables this effect of
+upper-case characters.  The default value of this variable is
+@code{not-yanks}, which makes search case-sensitive if there are
+upper-case letters in the search string, and also causes text yanked
+into the search string (@pxref{Isearch Yank}) to be down-cased, so
+that such searches are case-insensitive by default.
 
 @vindex case-fold-search
   If you set the variable @code{case-fold-search} to @code{nil}, then
@@ -1572,9 +1576,13 @@ searching for patterns.
 @cindex case folding in replace commands
   If the first argument of a replace command is all lower case, the
 command ignores case while searching for occurrences to
-replace---provided @code{case-fold-search} is non-@code{nil}.  If
-@code{case-fold-search} is set to @code{nil}, case is always significant
-in all searches.
+replace---provided @code{case-fold-search} is non-@code{nil} and
+@code{search-upper-case} is also non-@code{nil}.  If
+@code{search-upper-case} (@pxref{Lax Search, search-upper-case}) is
+@code{nil}, whether searching ignores case is determined by
+@code{case-fold-search} alone, regardless of letter-case of the
+command's first argument.  If @code{case-fold-search} is set to
+@code{nil}, case is always significant in all searches.
 
 @vindex case-replace
   In addition, when the @var{newstring} argument is all or partly lower

doc/lispref/lists.texi

@@ -1242,8 +1242,8 @@ compare @var{object} against the elements of the list.  For example:
      @result{} (b c b a)
 @end group
 @group
-(memq '(2) '((1) (2)))    ; @r{@code{(2)} and @code{(2)} are not @code{eq}.}
-     @result{} nil
+(memq '(2) '((1) (2)))    ; @r{The two @code{(2)}s need not be @code{eq}.}
+     @result{} @r{Unspecified; might be @code{nil} or @code{((2))}.}
 @end group
 @end example
 @end defun
@@ -1356,12 +1356,12 @@ Compare this with @code{memq}:
 
 @example
 @group
-(memql 1.2 '(1.1 1.2 1.3))  ; @r{@code{1.2} and @code{1.2} must be @code{eql}.}
+(memql 1.2 '(1.1 1.2 1.3))  ; @r{@code{1.2} and @code{1.2} are @code{eql}.}
      @result{} (1.2 1.3)
 @end group
 @group
-(memq 1.2 '(1.1 1.2 1.3))  ; @r{@code{1.2} and @code{1.2} need not be @code{eq}.}
-     @result{} nil         ; @r{... or it might be @code{(1.2 1.3)}.}
+(memq 1.2 '(1.1 1.2 1.3))  ; @r{The two @code{1.2}s need not be @code{eq}.}
+     @result{} @r{Unspecified; might be @code{nil} or @code{(1.2 1.3)}.}
 @end group
 @end example
 @end defun
@@ -1380,12 +1380,12 @@ Compare this with @code{memq}:
 
 @example
 @group
-(member (list 2) '((1) (2)))  ; @r{@code{(list 2)} and @code{(2)} are @code{equal}.}
+(member '(2) '((1) (2)))  ; @r{@code{(2)} and @code{(2)} are @code{equal}.}
      @result{} ((2))
 @end group
 @group
-(memq (list 2) '((1) (2)))    ; @r{@code{(list 2)} and @code{(2)} are not @code{eq}.}
-     @result{} nil
+(memq '(2) '((1) (2)))    ; @r{The two @code{(2)}s need not be @code{eq}.}
+     @result{} @r{Unspecified; might be @code{nil} or @code{(2)}.}
 @end group
 @group
 ;; @r{Two strings with the same contents are @code{equal}.}
@@ -1626,7 +1626,7 @@ keys may not be symbols:
         ("compound leaves" . horsechestnut)))
 
 (assq "simple leaves" leaves)
-     @result{} @r{Unspecified; might be @code{nil} or non-@code{nil}.}
+     @result{} @r{Unspecified; might be @code{nil} or @code{("simple leaves" . oak)}.}
 (assoc "simple leaves" leaves)
      @result{} ("simple leaves" . oak)
 @end smallexample

lisp/desktop.el

@@ -1017,13 +1017,16 @@ Frames with a non-nil `desktop-dont-save' parameter are not saved."
 
 ;;;###autoload
 (defun desktop-save (dirname &optional release only-if-changed version)
-  "Save the desktop in a desktop file.
-Parameter DIRNAME specifies where to save the desktop file.
-Optional parameter RELEASE says whether we're done with this
-desktop.  If ONLY-IF-CHANGED is non-nil, compare the current
-desktop information to that in the desktop file, and if the
-desktop information has not changed since it was last saved then
-do not rewrite the file.
+  "Save the state of Emacs in a desktop file in directory DIRNAME.
+Optional argument RELEASE non-nil says we're done with this
+desktop, in which case this function releases the lock of the
+desktop file in DIRNAME.
+If ONLY-IF-CHANGED is non-nil, compare the current desktop
+information to that in the desktop file, and if the desktop
+information has not changed since it was last saved, then do
+not rewrite the file.
+
+To restore the desktop, use `desktop-read'.
 
 This function can save the desktop in either format version
 208 (which only Emacs 25.1 and later can read) or version
@@ -1033,14 +1036,20 @@ it was last saved, or version 208 when writing a fresh desktop
 file.
 
 To upgrade a version 206 file to version 208, call this command
-explicitly with a bare prefix argument: C-u M-x desktop-save.
-You are recommended to do this once you have firmly upgraded to
-Emacs 25.1 (or later).  To downgrade a version 208 file to version
-206, use a double command prefix: C-u C-u M-x desktop-save.
-Confirmation will be requested in either case.  In a non-interactive
-call, VERSION can be given as an integer, either 206 or 208, which
-will be accepted as the format version in which to save the file
-without further confirmation."
+explicitly with a prefix argument: \\[universal-argument] \\[desktop-save].
+If you are upgrading from Emacs 24 or older, we recommed to do
+this once you decide you no longer need compatibility with versions
+of Emacs before 25.1.
+
+To downgrade a version 208 file to version 206, use a double prefix
+argument: \\[universal-argument] \\[universal-argument] \\[desktop-save].
+
+Emacs will ask for confirmation when you upgrade or downgrade your
+desktop file.
+
+In a non-interactive call, VERSION can be given as an integer, either
+206 or 208, to specify the format version in which to save the file,
+no questions asked."
   (interactive (list
                 ;; Or should we just use (car desktop-path)?
                 (let ((default (if (member "." desktop-path)

lisp/replace.el

@@ -340,13 +340,17 @@ that reads FROM-STRING, or invoke replacements from
 incremental search with a key sequence like `C-s C-s M-%'
 to use its current search string as the string to replace.
 
-Matching is independent of case if `case-fold-search' is non-nil and
-FROM-STRING has no uppercase letters.  Replacement transfers the case
-pattern of the old text to the new text, if `case-replace' and
-`case-fold-search' are non-nil and FROM-STRING has no uppercase
-letters.  (Transferring the case pattern means that if the old text
-matched is all caps, or capitalized, then its replacement is upcased
-or capitalized.)
+Matching is independent of case if both `case-fold-search'
+and `search-upper-case' are non-nil and FROM-STRING has no
+uppercase letters; if `search-upper-case' is nil, then
+whether matching ignores case depends on `case-fold-search'
+regardless of whether there are uppercase letters in FROM-STRING.
+Replacement transfers the case pattern of the old text to the
+new text, if both `case-fold-search' and `case-replace' are
+non-nil and FROM-STRING has no uppercase letters.
+\(Transferring the case pattern means that if the old text
+matched is all caps, or capitalized, then its replacement is
+respectively upcased or capitalized.)
 
 Ignore read-only matches if `query-replace-skip-read-only' is non-nil,
 ignore hidden matches if `search-invisible' is nil, and ignore more
@@ -402,13 +406,16 @@ that reads REGEXP, or invoke replacements from
 incremental search with a key sequence like `C-M-s C-M-s C-M-%'
 to use its current search regexp as the regexp to replace.
 
-Matching is independent of case if `case-fold-search' is non-nil and
-REGEXP has no uppercase letters.  Replacement transfers the case
-pattern of the old text to the new text, if `case-replace' and
-`case-fold-search' are non-nil and REGEXP has no uppercase letters.
-\(Transferring the case pattern means that if the old text matched is
-all caps, or capitalized, then its replacement is upcased or
-capitalized.)
+Matching is independent of case if both `case-fold-search'
+and `search-upper-case' are non-nil and REGEXP has no uppercase
+letters; if `search-upper-case' is nil, then whether matching
+ignores case depends on `case-fold-search' regardless of whether
+there are uppercase letters in REGEXP.
+Replacement transfers the case pattern of the old text to the new
+text, if both `case-fold-search' and `case-replace' are non-nil
+and REGEXP has no uppercase letters.  (Transferring the case pattern
+means that if the old text matched is all caps, or capitalized,
+then its replacement is respectively upcased or capitalized.)
 
 Ignore read-only matches if `query-replace-skip-read-only' is non-nil,
 ignore hidden matches if `search-invisible' is nil, and ignore more