Merge from origin/emacs-26

5172fa02cc Prefer HTTPS to HTTP for gnu.org
8cdd8b920a Merge from Gnulib
60b7668b89 Keep eww buffer current when looking up CSS on MDN
bd49b6f1b3 Workaround for faulty localtime() under macOS 10.6
913808e224 Doc amendment for syntax-ppss.
98dc91fda8 Remove incorrect NEWS entry about 'find-library'
539d8626cd Remove inadvertent changes to syntax.texi in last commit.
8c18dcbc78 Amend documentation for text-quoting-style becoming a user...
5f76ac150a Make the value nil in text-quoting-style mean what it does...
d5e4e004fa Make text-quoting-style customizable.  Introduce t and new...
1ba3471b9b eshell.texi improvements
7abb5c3960 Fix ns-win.el on GNUstep
07ea5ef99a Fix reference style in org.texi
b03b4f6d79 Improve handling of iconification of child frames (Bug#28611)
ba9139c501 Revert "Don't lose arguments to eshell aliases (Bug#27954)"
43fac3beae Make "unsafe directory" error message more informative (Bu...
c59ddb2120 Fix slot typecheck in eieio-persistent
8b2ab5014b Fix semantic-ia-fast-jump
5b45e7e1c3 Bind vc-region-history
f172894595 Exit macro definition on undefined keys
289fe6c0d1 Reset bidi-paragraph-direction on article rendering
a4f7518817 Fix url-http use of url-current-object
4a755ed421 Avoid assertions in vc-hg.el on MS-Windows
cb93a6ce72 Improve documentation of 'copy-sequence'
200ef6f721 Minor update of ack.texi
cb407d3e87 * doc/emacs/emacs.texi (Acknowledgments): Add more contrib...
82b6c765ff Improve indexing of multi-file/buffer Isearch commands
645ff6c702 Add CAM02 JCh and CAM02-UCS J'a'b' conversions
157007b58e Fix uses of @kindex in the Emacs manual
63a45e8837 Merge branch 'emacs-26' of git.savannah.gnu.org:/srv/git/e...
3ab2f9bbb9 Merge from gnulib
cbc8324488 Prefer HTTPS to HTTP for gnu.org
bbda601d1d ; Spelling fixes
695cf5300b Wait for frame visibility with timeout in w32term too
e1f6e3127a Bring back the busy wait after x_make_frame_visible (Bug#2...
bccf635217 ; * src/gtkutil.c (xg_check_special_colors): Add another G...
f428757cdb Merge branch 'emacs-26' of git.savannah.gnu.org:/srv/git/e...
26d58f0c58 ; Standardize license notices
73dba0f466 Fix last doc string change in simple.el

11 files changed, 124 insertions, 60 deletions

diff --git a/doc/lispref/ChangeLog.1 b/doc/lispref/ChangeLog.1
index 490f216b4cf..3fab757c963 100644
--- a/doc/lispref/ChangeLog.1
+++ b/doc/lispref/ChangeLog.1
@@ -497,7 +497,7 @@
         Improve doc for use of 'int', and discuss 'ssize_t'.
         * internals.texi (C Integer Types): Mention 'int' for other
         randomish values that lie in 'int' range.  Mention 'ssize_t'.  See:
-        http://lists.gnu.org/archive/html/emacs-devel/2014-10/msg00019.html
+        https://lists.gnu.org/archive/html/emacs-devel/2014-10/msg00019.html
 
         Use AUTO_CONS instead of SCOPED_CONS, etc.
         * internals.texi (Stack-allocated Objects):
@@ -971,7 +971,7 @@
 
         * markers.texi (Moving Marker Positions): Clarify guidance about
         when to move markers and when to create a new one, as discussed at
-        http://debbugs.gnu.org/cgi/bugreport.cgi?bug=16818#17
+        https://debbugs.gnu.org/cgi/bugreport.cgi?bug=16818#17
 
 2014-03-02  Glenn Morris  <rgm@gnu.org>
 
@@ -2154,7 +2154,7 @@
 
         * internals.texi (C Integer Types): New section.
         This follows up and records an email in
-        <http://lists.gnu.org/archive/html/emacs-devel/2012-07/msg00496.html>.
+        <https://lists.gnu.org/archive/html/emacs-devel/2012-07/msg00496.html>.
 
 2012-12-10  Stefan Monnier  <monnier@iro.umontreal.ca>
 
@@ -2475,7 +2475,7 @@
         * os.texi (Time of Day):
         Update for new time stamp format (HIGH LOW MICROSEC PICOSEC).
         These instances were missed the first time around.
-        Problem reported by Glenn Morris in <http://bugs.gnu.org/12706#25>.
+        Problem reported by Glenn Morris in <https://bugs.gnu.org/12706#25>.
 
 2012-10-24  Chong Yidong  <cyd@gnu.org>
 
@@ -6288,7 +6288,7 @@
 2009-04-11  Eli Zaretskii  <eliz@gnu.org>
 
         * display.texi (Overlays): Overlays don't scale well.  See
-        http://lists.gnu.org/archive/html/emacs-devel/2009-04/msg00243.html.
+        https://lists.gnu.org/archive/html/emacs-devel/2009-04/msg00243.html.
 
 2009-04-10  Chong Yidong  <cyd@stupidchicken.com>
 
diff --git a/doc/lispref/control.texi b/doc/lispref/control.texi
index 401a999cf23..4eddbe9c122 100644
--- a/doc/lispref/control.texi
+++ b/doc/lispref/control.texi
@@ -1101,13 +1101,10 @@ These examples show typical uses of @code{error}:
 error symbol @code{error}, and a list containing the string returned by
 @code{format-message}.
 
-The @code{text-quoting-style} variable controls what quotes are
-generated; @xref{Keys in Documentation}.  A call using a format like
-@t{"Missing `%s'"} with grave accents and apostrophes typically
-generates a message like @t{"Missing ‘foo’"} with matching curved
-quotes.  In contrast, a call using a format like @t{"Missing '%s'"}
-with only apostrophes typically generates a message like @t{"Missing
-’foo’"} with only closing curved quotes, an unusual style in English.
+Typically grave accent and apostrophe in the format translate to
+matching curved quotes, e.g., @t{"Missing `%s'"} might result in
+@t{"Missing ‘foo’"}.  @xref{Text Quoting Style}, for how to influence
+or inhibit this translation.
 
 @strong{Warning:} If you want to use your own string as an error message
 verbatim, don't just write @code{(error @var{string})}.  If @var{string}
diff --git a/doc/lispref/display.texi b/doc/lispref/display.texi
index 3dae984f339..afd09cfb330 100644
--- a/doc/lispref/display.texi
+++ b/doc/lispref/display.texi
@@ -265,13 +265,10 @@ properties, it is displayed with the specified faces (@pxref{Faces}).
 The string is also added to the @file{*Messages*} buffer, but without
 text properties (@pxref{Logging Messages}).
 
-The @code{text-quoting-style} variable controls what quotes are
-generated; @xref{Keys in Documentation}.  A call using a format like
-@t{"Missing `%s'"} with grave accents and apostrophes typically
-generates a message like @t{"Missing ‘foo’"} with matching curved
-quotes.  In contrast, a call using a format like @t{"Missing '%s'"}
-with only apostrophes typically generates a message like @t{"Missing
-’foo’"} with only closing curved quotes, an unusual style in English.
+Typically grave accent and apostrophe in the format translate to
+matching curved quotes, e.g., @t{"Missing `%s'"} might result in
+@t{"Missing ‘foo’"}.  @xref{Text Quoting Style}, for how to influence
+or inhibit this translation.
 
 In batch mode, the message is printed to the standard error stream,
 followed by a newline.
@@ -7035,7 +7032,7 @@ window display table nor a buffer display table defined, or when Emacs
 is outputting text to the standard output or error streams.  Although its
 default is typically @code{nil}, in an interactive session if the
 terminal cannot display curved quotes, its default maps curved quotes
-to ASCII approximations.  @xref{Keys in Documentation}.
+to ASCII approximations.  @xref{Text Quoting Style}.
 @end defvar
 
 The @file{disp-table} library defines several functions for changing
diff --git a/doc/lispref/doclicense.texi b/doc/lispref/doclicense.texi
index 542edaad258..eaf3da0e92d 100644
--- a/doc/lispref/doclicense.texi
+++ b/doc/lispref/doclicense.texi
@@ -414,7 +414,7 @@ The Free Software Foundation may publish new, revised versions
 of the GNU Free Documentation License from time to time.  Such new
 versions will be similar in spirit to the present version, but may
 differ in detail to address new problems or concerns.  See
-@uref{https://www.gnu.org/copyleft/}.
+@uref{https://www.gnu.org/licenses/}.
 
 Each version of the License is given a distinguishing version number.
 If the Document specifies that a particular numbered version of this
diff --git a/doc/lispref/elisp.texi b/doc/lispref/elisp.texi
index 4cbcdf855d1..c7525945845 100644
--- a/doc/lispref/elisp.texi
+++ b/doc/lispref/elisp.texi
@@ -940,6 +940,7 @@ Documentation
 * Documentation Basics::    Where doc strings are defined and stored.
 * Accessing Documentation:: How Lisp programs can access doc strings.
 * Keys in Documentation::   Substituting current key bindings.
+* Text Quoting Style::      Quotation marks in doc strings and messages.
 * Describing Characters::   Making printable descriptions of
                               non-printing characters and key sequences.
 * Help Functions::          Subroutines used by Emacs help facilities.
diff --git a/doc/lispref/frames.texi b/doc/lispref/frames.texi
index f66ecee8e8e..07a8b825026 100644
--- a/doc/lispref/frames.texi
+++ b/doc/lispref/frames.texi
@@ -3076,15 +3076,14 @@ as long as the parameter is not changed or reset.  Technically, this
 makes the child frame's window-system window a child window of the
 parent frame's window-system window.
 
-@cindex top-level frame
 @cindex reparent frame
 @cindex nest frame
   The @code{parent-frame} parameter can be changed at any time.  Setting
 it to another frame @dfn{reparents} the child frame.  Setting it to
 another child frame makes the frame a @dfn{nested} child frame.  Setting
-it to @code{nil} restores the frame's status as a @dfn{top-level
-frame}---a frame whose window-system window is a child of its display's
-root window.
+it to @code{nil} restores the frame's status as a top-level frame---a
+frame whose window-system window is a child of its display's root
+window.
 
   Since child frames can be arbitrarily nested, a frame can be both a
 child and a parent frame.  Also, the relative roles of child and parent
@@ -3203,7 +3202,11 @@ a number of other ways as well.  Here we sketch a few of them:
 @item
 The semantics of maximizing and iconifying child frames is highly
 window-system dependent.  As a rule, applications should never invoke
-these operations for child frames.
+these operations for on frames.  By default, invoking
+@code{iconify-frame} on a child frame will try to iconify the top-level
+frame corresponding to that child frame instead.  To obtain a different
+behavior, users may customize the option @code{iconify-child-frame}
+described below.
 
 @item
 Raising, lowering and restacking child frames (@pxref{Raising and
@@ -3259,6 +3262,23 @@ frame in the largest empty area of an existing window.  This can be
 useful to avoid that a child frame obscures any text shown in that
 window.
 
+Customizing the following option can be useful to tweak the behavior of
+@code{iconify-frame} for child frames.
+
+@defvar iconify-child-frame
+This option tells Emacs how to proceed when it is asked to iconify a
+child frame.  If it is @code{nil}, @code{iconify-frame} will do nothing
+when invoked on a child frame.  If it is @code{iconify-top-level}, Emacs
+will try to iconify the top-level frame that is the ancestor of this
+child frame instead.  If it is @code{make-invisible}, Emacs will try to
+make this child frame invisible instead of iconifying it.
+
+Any other value means to try iconifying the child frame.  Since such an
+attempt may not be honored by all window managers and can even lead to
+making the child frame unresponsive to user actions, the default is to
+iconify the top level frame instead.
+@end defvar
+
 
 @node Mouse Tracking
 @section Mouse Tracking
diff --git a/doc/lispref/gpl.texi b/doc/lispref/gpl.texi
index 0e2e212acb1..c007dc06966 100644
--- a/doc/lispref/gpl.texi
+++ b/doc/lispref/gpl.texi
@@ -5,7 +5,7 @@
 @c hence no sectioning command or @node.
 
 @display
-Copyright @copyright{} 2007 Free Software Foundation, Inc. @url{http://fsf.org/}
+Copyright @copyright{} 2007 Free Software Foundation, Inc. @url{https://fsf.org/}
 
 Everyone is permitted to copy and distribute verbatim copies of this
 license document, but changing it is not allowed.
@@ -684,7 +684,7 @@ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE@.  See the GNU
 General Public License for more details.
 
 You should have received a copy of the GNU General Public License
-along with this program.  If not, see @url{http://www.gnu.org/licenses/}.
+along with this program.  If not, see @url{https://www.gnu.org/licenses/}.
 @end smallexample
 
 Also add information on how to contact you by electronic and paper mail.
@@ -707,11 +707,11 @@ use an ``about box''.
 You should also get your employer (if you work as a programmer) or school,
 if any, to sign a ``copyright disclaimer'' for the program, if necessary.
 For more information on this, and how to apply and follow the GNU GPL, see
-@url{http://www.gnu.org/licenses/}.
+@url{https://www.gnu.org/licenses/}.
 
 The GNU General Public License does not permit incorporating your
 program into proprietary programs.  If your program is a subroutine
 library, you may consider it more useful to permit linking proprietary
 applications with the library.  If this is what you want to do, use
 the GNU Lesser General Public License instead of this License.  But
-first, please read @url{http://www.gnu.org/philosophy/why-not-lgpl.html}.
+first, please read @url{https://www.gnu.org/licenses/why-not-lgpl.html}.
diff --git a/doc/lispref/help.texi b/doc/lispref/help.texi
index cb214113523..4aa9b95180e 100644
--- a/doc/lispref/help.texi
+++ b/doc/lispref/help.texi
@@ -33,6 +33,7 @@ Help, emacs, The GNU Emacs Manual}.
 * Documentation Basics::      Where doc strings are defined and stored.
 * Accessing Documentation::   How Lisp programs can access doc strings.
 * Keys in Documentation::     Substituting current key bindings.
+* Text Quoting Style::        Quotation marks in doc strings and messages.
 * Describing Characters::     Making printable descriptions of
                                 non-printing characters and key sequences.
 * Help Functions::            Subroutines used by Emacs help facilities.
@@ -336,6 +337,7 @@ specifies @var{mapvar}'s value as the keymap for any following
 (grave accent) stands for a left quote.
 This generates a left single quotation mark, an apostrophe, or a grave
 accent depending on the value of @code{text-quoting-style}.
+@xref{Text Quoting Style}.
 
 @item '
 (apostrophe) stands for a right quote.
@@ -351,25 +353,24 @@ and @samp{\=\=} puts @samp{\=} into the output.
 @strong{Please note:} Each @samp{\} must be doubled when written in a
 string in Emacs Lisp.
 
-@defvar text-quoting-style
+@defopt text-quoting-style
 @cindex curved quotes
 @cindex curly quotes
 The value of this variable is a symbol that specifies the style Emacs
-should use for single quotes in the wording of help and messages.
-If the variable's value is @code{curve}, the style is
-@t{‘like this’} with curved single quotes.  If the value is
-@code{straight}, the style is @t{'like this'} with straight
-apostrophes.  If the value is @code{grave},
-quotes are not translated and the style is @t{`like
-this'} with grave accent and apostrophe, the standard style
-before Emacs version 25.  The default value @code{nil}
-acts like @code{curve} if curved single quotes are displayable, and
-like @code{grave} otherwise.
-
-This variable can be used by experts on platforms that have problems
-with curved quotes.  As it is not intended for casual use, it is not a
-user option.
-@end defvar
+should use for single quotes in the wording of help and messages.  If
+the variable's value is @code{curve}, the style is @t{‘like this’}
+with curved single quotes.  If the value is @code{straight}, the style
+is @t{'like this'} with straight apostrophes.  If the value is
+@code{grave}, quotes are not translated and the style is @t{`like
+this'} with grave accent and apostrophe, the standard style before
+Emacs version 25.  The default value @code{nil} acts like @code{curve}
+if curved single quotes seem to be displayable, and like @code{grave}
+otherwise.
+
+This option is useful on platforms that have problems with curved
+quotes.  You can customize it freely according to your personal
+preference.
+@end defopt
 
 @defun substitute-command-keys string
 This function scans @var{string} for the above special sequences and
@@ -429,6 +430,53 @@ C-g             abort-recursive-edit
 strings---for instance, you can refer to functions, variables, and
 sections of this manual.  @xref{Documentation Tips}, for details.
 
+@node Text Quoting Style
+@section Text Quoting Style
+
+  Typically, grave accents and apostrophes are treated specially in
+documentation strings and diagnostic messages, and translate to matching
+single quotation marks (also called ``curved quotes'').  For example,
+the documentation string @t{"Alias for `foo'."} and the function call
+@code{(message "Alias for `foo'.")} both translate to @t{"Alias for
+‘foo’."}.  Less commonly, Emacs displays grave accents and apostrophes
+as themselves, or as apostrophes only (e.g., @t{"Alias for 'foo'."}).
+Documentation strings and message formats should be written so that
+they display well with any of these styles.  For example, the
+documentation string @t{"Alias for 'foo'."} is probably not what you
+want, as it can display as @t{"Alias for ’foo’."}, an unusual style in
+English.
+
+  Sometimes you may need to display a grave accent or apostrophe
+without translation, regardless of text quoting style.  In a
+documentation string, you can do this with escapes.  For example, in
+the documentation string @t{"\\=`(a ,(sin 0)) ==> (a 0.0)"} the grave
+accent is intended to denote Lisp code, so it is escaped and displays
+as itself regardless of quoting style.  In a call to @code{message} or
+@code{error}, you can avoid translation by using a format @t{"%s"}
+with an argument that is a call to @code{format}.  For example,
+@code{(message "%s" (format "`(a ,(sin %S)) ==> (a %S)" x (sin x)))}
+displays a message that starts with grave accent regardless of text
+quoting style.
+
+@defopt text-quoting-style
+@cindex curved quotes
+@cindex curly quotes
+The value of this user option is a symbol that specifies the style
+Emacs should use for single quotes in the wording of help and
+messages.  If the option's value is @code{curve}, the style is
+@t{‘like this’} with curved single quotes.  If the value is
+@code{straight}, the style is @t{'like this'} with straight
+apostrophes.  If the value is @code{grave}, quotes are not translated
+and the style is @t{`like this'} with grave accent and apostrophe, the
+standard style before Emacs version 25.  The default value @code{nil}
+acts like @code{curve} if curved single quotes seem to be displayable,
+and like @code{grave} otherwise.
+
+This option is useful on platforms that have problems with curved
+quotes.  You can customize it freely according to your personal
+preference.
+@end defopt
+
 @node Describing Characters
 @section Describing Characters for Help Messages
 @cindex describe characters and events
diff --git a/doc/lispref/sequences.texi b/doc/lispref/sequences.texi
index c7cf9f5e1af..5ae1567c128 100644
--- a/doc/lispref/sequences.texi
+++ b/doc/lispref/sequences.texi
@@ -155,7 +155,10 @@ This function generalizes @code{aref} (@pxref{Array Functions}) and
 @cindex copying sequences
 This function returns a copy of @var{seqr}, which should be either a
 sequence or a record.  The copy is the same type of object as the
-original, and it has the same elements in the same order.
+original, and it has the same elements in the same order.  However, if
+@var{seqr} is empty, like a string or a vector of zero length, the
+value returned by this function might not be a copy, but an empty
+object of the same type and identical to @var{seqr}.
 
 Storing a new element into the copy does not affect the original
 @var{seqr}, and vice versa.  However, the elements of the copy
diff --git a/doc/lispref/strings.texi b/doc/lispref/strings.texi
index 219225d412b..dd004927caf 100644
--- a/doc/lispref/strings.texi
+++ b/doc/lispref/strings.texi
@@ -826,17 +826,14 @@ to the produced string representations of the argument @var{objects}.
 @defun format-message string &rest objects
 @cindex curved quotes, in formatted messages
 @cindex curly quotes, in formatted messages
-@cindex @code{text-quoting-style}, and formatting messages
 This function acts like @code{format}, except it also converts any
 grave accents (@t{`}) and apostrophes (@t{'}) in @var{string} as per the
 value of @code{text-quoting-style}.
 
-A format that quotes with grave accents and apostrophes @t{`like
-this'} typically generates curved quotes @t{‘like this’}.  In
-contrast, a format that quotes with only apostrophes @t{'like this'}
-typically generates two closing curved quotes @t{’like this’}, an
-unusual style in English.  @xref{Keys in Documentation}, for how the
-@code{text-quoting-style} variable affects generated quotes.
+Typically grave accent and apostrophe in the format translate to
+matching curved quotes, e.g., @t{"Missing `%s'"} might result in
+@t{"Missing ‘foo’"}.  @xref{Text Quoting Style}, for how to influence
+or inhibit this translation.
 @end defun
 
 @cindex @samp{%} in format
diff --git a/doc/lispref/syntax.texi b/doc/lispref/syntax.texi
index e3ae53536f9..b37f2b22b82 100644
--- a/doc/lispref/syntax.texi
+++ b/doc/lispref/syntax.texi
@@ -751,7 +751,8 @@ position.  This function does that conveniently.
 
 @defun syntax-ppss &optional pos
 This function returns the parser state that the parser would reach at
-position @var{pos} starting from the beginning of the buffer.
+position @var{pos} starting from the beginning of the visible portion
+of the buffer.
 @iftex
 See the next section for
 @end iftex
@@ -762,11 +763,11 @@ for a description of the parser state.
 
 The return value is the same as if you call the low-level parsing
 function @code{parse-partial-sexp} to parse from the beginning of the
-buffer to @var{pos} (@pxref{Low-Level Parsing}).  However,
-@code{syntax-ppss} uses a cache to speed up the computation.  Due to
-this optimization, the second value (previous complete subexpression)
-and sixth value (minimum parenthesis depth) in the returned parser
-state are not meaningful.
+visible portion of the buffer to @var{pos} (@pxref{Low-Level
+Parsing}).  However, @code{syntax-ppss} uses caches to speed up the
+computation.  Due to this optimization, the second value (previous
+complete subexpression) and sixth value (minimum parenthesis depth) in
+the returned parser state are not meaningful.
 
 This function has a side effect: it adds a buffer-local entry to
 @code{before-change-functions} (@pxref{Change Hooks}) for