diff -up libX11-1.8.10/modules/im/ximcp/imDefFlt.c.jx libX11-1.8.10/modules/im/ximcp/imDefFlt.c
--- libX11-1.8.10/modules/im/ximcp/imDefFlt.c.jx	2024-08-04 19:08:38.884682300 +0800
+++ libX11-1.8.10/modules/im/ximcp/imDefFlt.c	2024-08-04 19:09:16.340626000 +0800
@@ -143,7 +143,7 @@
 {
     Xim		im = (Xim)ic->core.im;
 
-    if (_XimIsFabricatedSerial(im, ev)) {
+    if ((ev->keycode == 0) || _XimIsFabricatedSerial(im, ev)) {
 	_XimPendingFilter(ic);
 	_XimUnfabricateSerial(im, ic, ev);
 	return NOTFILTERD;
diff -up libX11-1.8.10/modules/im/ximcp/imDefLkup.c.jx libX11-1.8.10/modules/im/ximcp/imDefLkup.c
--- libX11-1.8.10/modules/im/ximcp/imDefLkup.c.jx	2024-08-04 19:09:16.340626000 +0800
+++ libX11-1.8.10/modules/im/ximcp/imDefLkup.c	2024-08-04 19:09:16.340626000 +0800
@@ -333,6 +333,17 @@
     XEvent	*ev,
     Bool	 sync)
 {
+    /*
+     * Don't forward a key event which has keycode=0.
+     * keycode=0 is reserved for special purpose to let Xmb/wcLookupString()
+     * functions know that there is a commited string available from IM.
+     */
+    if (((ev->type == KeyPress) || (ev->type == KeyRelease))) {
+        if (((XKeyEvent *)ev)->keycode == 0) {
+            return True;
+        }
+    }
+
 #ifdef EXT_FORWARD
     if (((ev->type == KeyPress) || (ev->type == KeyRelease)))
 	if (_XimExtForwardKeyEvent(ic, (XKeyEvent *)ev, sync))
@@ -703,6 +714,19 @@
     else
 	ic->private.proto.commit_info = info->next;
     Xfree(info);
+
+    /*
+     * "Commit" uses fabricated flag to process a commited string
+     * from IM engine.  
+     * Turn off the fabricated flag here (unregister the commited
+     * information function). Otherwise, next regular key press
+     * event will be ignored at _XimProtoKeypressFilter() and it
+     * will not be passed to IM engine.
+     */
+    if (IS_FABRICATED(ic)) {
+        UNMARK_FABRICATED(ic);
+    }
+
     return;
 }