Merge from origin/emacs-27

c04b92104c Add commentary in gtkutil.c
6290850dac Consistently stylize eldoc as ElDoc in prose
136e931189 Improve documentation of "C-u C-x ="
1f52771fd3 Mention floating rounding issues
c892ae65b4 Repair global-auto-revert-ignore-modes (bug#42271)
3a446a02fb ; * src/xdisp.c (decode_mode_spec): Fix commentary.
79f381b4a6 One more improvement of left/right-fringe display spec docs
1279bdb072 Another clarification of left/right-fringe display spec

# Conflicts:
#	doc/emacs/programs.texi

doc/emacs/custom.texi

@@ -1223,7 +1223,7 @@ other context has no special meaning.
 disable a minor mode in a local variables list, use the @code{eval}
 keyword with a Lisp expression that runs the mode command
 (@pxref{Minor Modes}).  For example, the following local variables
-list enables Eldoc mode (@pxref{Lisp Doc}) by calling
+list enables ElDoc mode (@pxref{Lisp Doc}) by calling
 @code{eldoc-mode} with no argument (calling it with an argument of 1
 would do the same), and disables Font Lock mode (@pxref{Font Lock}) by
 calling @code{font-lock-mode} with an argument of @minus{}1.

doc/emacs/modes.texi

@@ -126,7 +126,7 @@ see which mode is actually being entered.
   Mode hooks are commonly used to enable minor modes (@pxref{Minor
 Modes}).  For example, you can put the following lines in your init
 file to enable Flyspell minor mode in all text-based major modes
-(@pxref{Spelling}), and Eldoc minor mode in Emacs Lisp mode
+(@pxref{Spelling}), and ElDoc minor mode in Emacs Lisp mode
 (@pxref{Lisp Doc}):
 
 @example

doc/emacs/mule.texi

@@ -192,13 +192,19 @@ What keys to type to input the character in the current input method
 
 @item
 The character's encodings, both internally in the buffer, and externally
-if you were to save the file.
+if you were to save the buffer to a file.
 
 @item
 If you are running Emacs on a graphical display, the font name and
 glyph code for the character.  If you are running Emacs on a text
 terminal, the code(s) sent to the terminal.
 
+@item
+If the character was composed on display with any following characters
+to form one or more grapheme clusters, the composition information:
+the font glyphs if the frame is on a graphical display, else the
+characters that were composed.
+
 @item
 The character's text properties (@pxref{Text Properties,,,
 elisp, the Emacs Lisp Reference Manual}), including any non-default

doc/emacs/programs.texi

@@ -1260,16 +1260,16 @@ the WoMan Info manual, which is distributed with Emacs.
 to view the built-in documentation for the Lisp functions and
 variables that you want to use.  @xref{Name Help}.
 
-@cindex Eldoc mode
+@cindex ElDoc mode
 @findex eldoc-mode
 @findex global-eldoc-mode
-  Eldoc is a buffer-local minor mode that helps with looking up Lisp
+  ElDoc is a buffer-local minor mode that helps with looking up Lisp
 documentation.  When it is enabled, the echo area displays some useful
 information whenever there is a Lisp function or variable at point;
 for a function, it shows the argument list, and for a variable it
 shows the first line of the variable's documentation string.  To
-toggle Eldoc mode, type @kbd{M-x eldoc-mode}.  There's also a Global
-Eldoc mode, which is turned on by default, and affects buffers whose
+toggle ElDoc mode, type @kbd{M-x eldoc-mode}.  There's also a Global
+ElDoc mode, which is turned on by default, and affects buffers whose
 major mode sets the variables described below.  Use @w{@kbd{M-x
 global-eldoc-mode}} to turn it off globally.
 

doc/lispref/display.texi

@@ -4275,9 +4275,15 @@ a display specification has the form
 @var{fringe} is either the symbol @code{left-fringe} or
 @code{right-fringe}.  @var{bitmap} is a symbol identifying the bitmap
 to display.  The optional @var{face} names a face whose foreground and
-background colors are to be used to display the bitmap; this face is
-automatically merged with the @code{fringe} face.  If @var{face} is
-omitted, that means to use the @code{default} face.
+background colors are to be used to display the bitmap, using the
+attributes of the @code{fringe} face for colors that @var{face} didn't
+specify.  If @var{face} is omitted, that means to use the attributes
+of the @code{default} face for the colors which the @code{fringe} face
+didn't specify.  For predictable results that don't depend on the
+attributes of the @code{default} and @code{fringe} faces, we recommend
+you never omit @var{face}, but always provide a specific face.  In
+particular, if you want the bitmap to be always displayed in the
+@code{fringe} face, use @code{fringe} as @var{face}.
 
   For instance, to display an arrow in the left fringe, using the
 @code{warning} face, you could say something like:

doc/lispref/numbers.texi

@@ -227,6 +227,9 @@ you are using.  On all computers supported by Emacs, this is
 and is discussed further in David Goldberg's paper
 ``@url{https://docs.oracle.com/cd/E19957-01/806-3568/ncg_goldberg.html,
 What Every Computer Scientist Should Know About Floating-Point Arithmetic}''.
+On modern platforms, floating-point operations follow the IEEE-754
+standard closely; however, results are not always rounded correctly on
+some obsolescent platforms, notably 32-bit x86.
 
   The read syntax for floating-point numbers requires either a decimal
 point, an exponent, or both.  Optional signs (@samp{+} or @samp{-})

etc/NEWS.22

@@ -5239,7 +5239,7 @@ has no effect on systems with case-insensitive file names.
 hooks.  `run-mode-hooks' does this automatically.
 
 *** Major modes can define `eldoc-documentation-function'
-locally to provide Eldoc functionality by some method appropriate to
+locally to provide ElDoc functionality by some method appropriate to
 the language.
 
 *** Use the new function `run-mode-hooks' to run the major mode's mode hook.

etc/NEWS.23

@@ -1779,7 +1779,7 @@ to update it to the new VC.
 If `default-directory' is a remote file name, subprocesses are started
 on the corresponding remote system.
 
-*** Eldoc highlights the function argument under point
+*** ElDoc highlights the function argument under point
 with the face `eldoc-highlight-function-argument'.
 
 *** In Etags, the --members option is now the default.

lisp/autorevert.el

@@ -545,7 +545,7 @@ specifies in the mode line."
                       ;; we wouldn't know when to revert it otherwise.
                       (not (eq buffer-stale-function
                                #'buffer-stale--default-function))))
-             (not (memq 'major-mode global-auto-revert-ignore-modes))
+             (not (memq major-mode global-auto-revert-ignore-modes))
              (or (null global-auto-revert-ignore-buffer)
                  (if (functionp global-auto-revert-ignore-buffer)
                      (not (funcall global-auto-revert-ignore-buffer

lisp/progmodes/python.el

@@ -34,7 +34,7 @@
 ;; Implements Syntax highlighting, Indentation, Movement, Shell
 ;; interaction, Shell completion, Shell virtualenv support, Shell
 ;; package support, Shell syntax highlighting, Pdb tracking, Symbol
-;; completion, Skeletons, FFAP, Code Check, Eldoc, Imenu.
+;; completion, Skeletons, FFAP, Code Check, ElDoc, Imenu.
 
 ;; Syntax highlighting: Fontification of code is provided and supports
 ;; python's triple quoted strings properly.
@@ -216,7 +216,7 @@
 ;; Code check: Check the current file for errors with `python-check'
 ;; using the program defined in `python-check-command'.
 
-;; Eldoc: returns documentation for object at point by using the
+;; ElDoc: returns documentation for object at point by using the
 ;; inferior python subprocess to inspect its documentation.  As you
 ;; might guessed you should run `python-shell-send-buffer' from time
 ;; to time to get better results too.
@@ -4474,7 +4474,7 @@ See `python-check-command' for the default."
                          (format python-check-buffer-name command)))))
 
 
-;;; Eldoc
+;;; ElDoc
 
 (defcustom python-eldoc-setup-code
   "def __PYDOC_get_help(obj):
@@ -4591,7 +4591,7 @@ fetching."
     (with-timeout (python-eldoc-function-timeout
                    (if python-eldoc-function-timeout-permanent
                        (progn
-                         (message "Eldoc echo-area display muted in this buffer, see `python-eldoc-function'")
+                         (message "ElDoc echo-area display muted in this buffer, see `python-eldoc-function'")
                          (setq python-eldoc-get-doc nil))
                      (message "`python-eldoc-function' timed out, see `python-eldoc-function-timeout'")))
       (python-eldoc--get-doc-at-point))))

src/gtkutil.c

@@ -17,6 +17,13 @@ GNU General Public License for more details.
 You should have received a copy of the GNU General Public License
 along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 
+/* FIXME: This code is problematic; it misuses GTK, so the GTK
+   developers don't think they should fix the resulting problems in GTK
+   itself.  The right way to fix this is by rewriting the code in Emacs
+   to use GTK3 properly.  As of 2020, there is a project to do this.
+   Talk with Yuuki Harano <masm+emacs@masm11.me> if you are interested
+   in doing substantial work on this.  */
+
 #include <config.h>
 
 #ifdef USE_GTK

src/xdisp.c

@@ -26387,7 +26387,7 @@ decode_mode_spec (struct window *w, register int c, int field_width,
 	height = WINDOW_TOTAL_LINES (w);
 	/* We cannot cope with w->start being outside of the
 	   accessible portion of the buffer; in particular,
-	   display_count_lines call below will infloop if called with
+	   display_count_lines call below might infloop if called with
 	   startpos_byte outside of the [BEGV_BYTE..ZV_BYTE] region.
 	   Such w->start means we were called in some "creative" way
 	   when the buffer's restriction was changed, but the window

test/lisp/progmodes/python-tests.el

@@ -3553,7 +3553,7 @@ def foo():
 ;;; Code check
 
 
-;;; Eldoc
+;;; ElDoc
 
 (ert-deftest python-eldoc--get-symbol-at-point-1 ()
   "Test paren handling."