Merge from origin/emacs-27

86cbc9d216 Make ignoring modifiers on IME input optional
32b97bb9e0 Ignore modifiers when processing WM_IME_CHAR messages
f641ef1a07 Improve documentation of 'font-spec'

# Conflicts:
#	etc/NEWS

doc/lispref/display.texi

@@ -3754,6 +3754,20 @@ Additional typographic style information for the font, such as
 The charset registry and encoding of the font, such as
 @samp{iso8859-1}.  The value should be a string or a symbol.
 
+@item :dpi
+The resolution in dots per inch for which the font is designed.  The
+value must be a non-negative number.
+
+@item :spacing
+The spacing of the font: proportional, dual, mono, or charcell.  The
+value should be either an integer (0 for proportional, 90 for dual,
+100 for mono, 110 for charcell) or a one-letter symbol (one of
+@code{P}, @code{D}, @code{M}, or @code{C}).
+
+@item :avgwidth
+The average width of the font in 1/10 pixel units.  The value should
+be a non-negative number.
+
 @item :script
 The script that the font must support (a symbol).
 

etc/NEWS.27

@@ -48,7 +48,7 @@ skip leading or trailing empty lines of the buffer.
 
 ** Tramp
 
-*** The user option 'tramp-completion-reread-directory-timeout' is made obsolete.
+*** The user option 'tramp-completion-reread-directory-timeout' is now obsolete.
 
 
 * New Modes and Packages in Emacs 27.2
@@ -62,6 +62,13 @@ skip leading or trailing empty lines of the buffer.
 
 * Changes in Emacs 27.2 on Non-Free Operating Systems
 
+** Emacs now ignores modifier keys when IME input is used.
+By default, pressing Ctrl, Shift, and Alt keys while using IME input
+will no longer apply the modifiers to the produced characters, as
+there are IMEs which use keys with modifiers to input some
+characters.  Customize the variable 'w32-ignore-modifiers-on-IME-input'
+to nil to get back the old behavior.
+
 
 * Installation Changes in Emacs 27.1
 

src/font.c

@@ -3945,6 +3945,23 @@ VALUE must be a non-negative integer or a floating point number
 specifying the font size.  It specifies the font size in pixels (if
 VALUE is an integer), or in points (if VALUE is a float).
 
+`:dpi'
+
+VALUE must be a non-negative number that specifies the resolution
+(dot per inch) for which the font is designed.
+
+`:spacing'
+
+VALUE specifies the spacing of the font: mono, proportional, charcell,
+or dual.  It can be either a number (0 for proportional, 90 for dual,
+100 for mono, 110 for charcell) or a 1-letter symbol: `P', `D', `M',
+or `C' (lower-case variants are also accepted).
+
+`:avgwidth'
+
+VALUE must be a non-negative integer specifying the average width of
+the font in 1/10 pixel units.
+
 `:name'
 
 VALUE must be a string of XLFD-style or fontconfig-style font name.

src/w32fns.c

@@ -4448,7 +4448,10 @@ w32_wnd_proc (HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
 	  int size, i;
 	  W32Msg wmsg;
 	  HIMC context = get_ime_context_fn (hwnd);
-	  wmsg.dwModifiers = w32_get_key_modifiers (wParam, lParam);
+	  wmsg.dwModifiers =
+	    w32_ignore_modifiers_on_IME_input
+	    ? 0
+	    : w32_get_key_modifiers (wParam, lParam);
 	  /* Get buffer size.  */
 	  size = get_composition_string_fn (context, GCS_RESULTSTR, NULL, 0);
 	  buffer = alloca (size);
@@ -10614,6 +10617,15 @@ tip frame.  */);
 	       doc: /* Non-nil means don't display the abort dialog when aborting.  */);
   w32_disable_abort_dialog = 0;
 
+  DEFVAR_BOOL ("w32-ignore-modifiers-on-IME-input",
+	       w32_ignore_modifiers_on_IME_input,
+	       doc: /* Whether to ignore modifier keys when processing input with IME.
+Some MS-Windows input methods use modifier keys such as Ctrl or Alt to input
+characters, in which case applying the modifiers will change the input.
+The default value of this variable is therefore t, to ignore modifier
+keys when IME input is received.  */);
+  w32_ignore_modifiers_on_IME_input = true;
+
 #if 0 /* TODO: Port to W32 */
   defsubr (&Sx_change_window_property);
   defsubr (&Sx_delete_window_property);