From f1d535da1ed2e7a70c6cf28fdcdca31d3f86a3f5 Mon Sep 17 00:00:00 2001
From: Po Lu <luangruo@yahoo.com>
Date: Wed, 16 Feb 2022 10:53:00 +0800
Subject: [PATCH] Decode keyboard input as latin-1 whenever appropriate

* src/keyboard.c (kbd_buffer_get_event_1): Use `coding'
property if present.

* src/termhooks.h (enum event_kind): Document meaning of
`coding' property on text strings.

* src/xterm.c (handle_one_xevent): Set coding property on text
to latin-1 if it was obtained with XLookupString.
---
 src/keyboard.c  | 10 +++++++++-
 src/termhooks.h | 12 +++++++++++-
 src/xterm.c     | 14 ++++++++++++++
 3 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/src/keyboard.c b/src/keyboard.c
index 800632aa25d..0747ab48205 100644
--- a/src/keyboard.c
+++ b/src/keyboard.c
@@ -3838,7 +3838,12 @@ clear_event (struct input_event *event)
 static Lisp_Object
 kbd_buffer_get_event_1 (Lisp_Object arg)
 {
-  return code_convert_string (arg, Vlocale_coding_system,
+  Lisp_Object coding_system = Fget_text_property (make_fixnum (0),
+						  Qcoding, arg);
+
+  return code_convert_string (arg, (!NILP (coding_system)
+				    ? coding_system
+				    : Vlocale_coding_system),
 			      Qnil, 0, false, 0);
 }
 
@@ -12477,6 +12482,9 @@ See also `pre-command-hook'.  */);
   DEFSYM (Qtouchscreen_end, "touchscreen-end");
   DEFSYM (Qtouchscreen_update, "touchscreen-update");
   DEFSYM (Qpinch, "pinch");
+
+  DEFSYM (Qcoding, "coding");
+
   Fset (Qecho_area_clear_hook, Qnil);
 
   DEFVAR_LISP ("lucid-menu-bar-dirty-flag", Vlucid_menu_bar_dirty_flag,
diff --git a/src/termhooks.h b/src/termhooks.h
index 4276d8ac2f2..0a9ab61afab 100644
--- a/src/termhooks.h
+++ b/src/termhooks.h
@@ -90,7 +90,17 @@ enum event_kind
 					   decoded and the decoded
 					   string's characters will be
 					   used as .code
-					   individually.  */
+					   individually.
+
+					   The string can have a
+					   property `coding', which
+					   should be a symbol
+					   describing a coding system
+					   to use to decode the string.
+
+					   If it is nil, then the
+					   locale coding system will
+					   be used.  */
   NON_ASCII_KEYSTROKE_EVENT,	/* .code is a number identifying the
 				   function key.  A code N represents
 				   a key whose name is
diff --git a/src/xterm.c b/src/xterm.c
index 568351d2e3d..bd8d5f892f3 100644
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -9132,6 +9132,7 @@ handle_one_xevent (struct x_display_info *dpyinfo,
   static XComposeStatus compose_status;
   XEvent configureEvent;
   XEvent next_event;
+  Lisp_Object coding;
 
   *finish = X_EVENT_NORMAL;
 
@@ -9784,6 +9785,7 @@ handle_one_xevent (struct x_display_info *dpyinfo,
     case KeyPress:
       x_display_set_last_user_time (dpyinfo, event->xkey.time);
       ignore_next_mouse_click_timeout = 0;
+      coding = Qlatin_1;
 
 #if defined (USE_X_TOOLKIT) || defined (USE_GTK)
       /* Dispatch KeyPress events when in menu.  */
@@ -9884,6 +9886,7 @@ handle_one_xevent (struct x_display_info *dpyinfo,
                                         &xkey, (char *) copy_bufptr,
                                         copy_bufsiz, &keysym,
                                         &status_return);
+	      coding = Qnil;
               if (status_return == XBufferOverflow)
                 {
                   copy_bufsiz = nbytes + 1;
@@ -10053,6 +10056,9 @@ handle_one_xevent (struct x_display_info *dpyinfo,
 	    inev.ie.kind = MULTIBYTE_CHAR_KEYSTROKE_EVENT;
 	    inev.ie.arg = make_unibyte_string ((char *) copy_bufptr, nbytes);
 
+	    Fput_text_property (make_fixnum (0), make_fixnum (nbytes),
+				Qcoding, coding, inev.ie.arg);
+
 	    if (keysym == NoSymbol)
 	      break;
 	  }
@@ -11444,6 +11450,8 @@ handle_one_xevent (struct x_display_info *dpyinfo,
 	      ptrdiff_t i;
 	      struct xi_device_t *device;
 
+	      coding = Qlatin_1;
+
 	      device = xi_device_from_id (dpyinfo, xev->deviceid);
 
 	      if (!device || !device->master_p)
@@ -11571,6 +11579,7 @@ handle_one_xevent (struct x_display_info *dpyinfo,
 						&xkey, (char *) copy_bufptr,
 						copy_bufsiz, &keysym,
 						&status_return);
+		      coding = Qnil;
 
 		      if (status_return == XBufferOverflow)
 			{
@@ -11617,6 +11626,8 @@ handle_one_xevent (struct x_display_info *dpyinfo,
 			      if (overflow)
 				nbytes = 0;
 			    }
+
+			  coding = Qnil;
 			}
 		      else
 #endif
@@ -11748,6 +11759,9 @@ handle_one_xevent (struct x_display_info *dpyinfo,
 
 		  inev.ie.kind = MULTIBYTE_CHAR_KEYSTROKE_EVENT;
 		  inev.ie.arg = make_unibyte_string (copy_bufptr, nbytes);
+
+		  Fput_text_property (make_fixnum (0), make_fixnum (nbytes),
+				      Qcoding, coding, inev.ie.arg);
 		  goto xi_done_keysym;
 		}
 
-- 
2.39.5