From c3c08b90b67ba42be06a260718c5b6e5939e0b25 Mon Sep 17 00:00:00 2001
From: Po Lu <luangruo@yahoo.com>
Date: Tue, 12 Apr 2022 21:29:02 +0800
Subject: [PATCH] Fix keyboard event device attribution on GTK+ 2

* src/xfns.c (setup_xi_event_mask): Select for raw keypress
events on GTK 2.
* src/xterm.c (handle_one_xevent): Set pending keystroke time
when a raw event is received.
* src/xterm.h (struct x_display_info): New flag
`pending_keystroke_time_special_p'.
---
 src/xfns.c  |  9 +++++++++
 src/xterm.c | 26 +++++++++++++++++++++++++-
 src/xterm.h |  8 ++++++++
 3 files changed, 42 insertions(+), 1 deletion(-)

diff --git a/src/xfns.c b/src/xfns.c
index 5cf3eb41996..2f90534c484 100644
--- a/src/xfns.c
+++ b/src/xfns.c
@@ -3688,6 +3688,15 @@ setup_xi_event_mask (struct frame *f)
   XISelectEvents (FRAME_X_DISPLAY (f),
 		  FRAME_X_WINDOW (f),
 		  &mask, 1);
+
+#if defined USE_GTK && !defined HAVE_GTK3
+  memset (m, 0, l);
+  XISetMask (m, XI_RawKeyPress);
+
+  XISelectEvents (FRAME_X_DISPLAY (f),
+		  FRAME_DISPLAY_INFO (f)->root_window,
+		  &mask, 1);
+#endif
   unblock_input ();
 }
 #endif
diff --git a/src/xterm.c b/src/xterm.c
index e922ab8fbb2..2999480659b 100644
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -14516,7 +14516,16 @@ handle_one_xevent (struct x_display_info *dpyinfo,
 	  pending_keystroke_time = dpyinfo->pending_keystroke_time;
 
 	  if (event->xkey.time >= pending_keystroke_time)
-	    dpyinfo->pending_keystroke_time = 0;
+	    {
+#if defined USE_GTK && !defined HAVE_GTK3
+	      if (!dpyinfo->pending_keystroke_time_special_p)
+#endif
+		dpyinfo->pending_keystroke_time = 0;
+#if defined USE_GTK && !defined HAVE_GTK3
+	      else
+		dpyinfo->pending_keystroke_time_special_p = false;
+#endif
+	    }
 #endif
 
 #ifdef USE_GTK
@@ -17781,6 +17790,21 @@ handle_one_xevent (struct x_display_info *dpyinfo,
 	      goto XI_OTHER;
 	    }
 
+#if defined USE_GTK && !defined HAVE_GTK3
+	  case XI_RawKeyPress:
+	    {
+	      XIRawEvent *raw_event = (XIRawEvent *) xi_event;
+
+	      /* This is the only way to attribute core keyboard
+		 events generated on GTK+ 2.x to the extension device
+		 that generated them.  */
+	      dpyinfo->pending_keystroke_time = raw_event->time;
+	      dpyinfo->pending_keystroke_source = raw_event->sourceid;
+	      dpyinfo->pending_keystroke_time_special_p = true;
+	      goto XI_OTHER;
+	    }
+#endif
+
 	  case XI_KeyRelease:
 #if defined HAVE_X_I18N || defined USE_GTK
 	    {
diff --git a/src/xterm.h b/src/xterm.h
index 85b773cf0bb..69313166db9 100644
--- a/src/xterm.h
+++ b/src/xterm.h
@@ -618,6 +618,14 @@ struct x_display_info
 
   Time pending_keystroke_time;
   int pending_keystroke_source;
+
+#if defined USE_GTK && !defined HAVE_GTK3
+  /* This means the two variables above shouldn't be reset the first
+     time a KeyPress event arrives, since they were set from a raw key
+     press event that was sent before the first (real, not sent by an
+     input method) core key event.  */
+  bool pending_keystroke_time_special_p;
+#endif
 #endif
 
 #ifdef HAVE_XKB
-- 
2.39.5