From 4bae06f5d5248e0cd001ef76ad884853a1705a91 Mon Sep 17 00:00:00 2001
From: Roman Savochenko <roman@oscada.org>
Date: Sun, 4 Aug 2019 16:38:55 +0300
Subject: [PATCH] krfb: Add a function for appending new symbols to the actual
 X-server keymap

This resolves bug 3014 and issue #11

Signed-off-by: Roman Savochenko <roman@oscada.org>
(cherry picked from commit b75ba2ef0d61d0d356a3a0fe9e581e5aaf29b7a4)
---
 krfb/krfb/rfbcontroller.cc | 53 ++++++++++++++++++++++++++++++++++++++
 krfb/krfb/rfbcontroller.h  |  1 +
 2 files changed, 54 insertions(+)

diff --git a/krfb/krfb/rfbcontroller.cc b/krfb/krfb/rfbcontroller.cc
index 0db57514..4cd0f7fb 100644
--- a/krfb/krfb/rfbcontroller.cc
+++ b/krfb/krfb/rfbcontroller.cc
@@ -184,9 +184,13 @@ const int KeyboardEvent::RIGHTSHIFT = 2;
 const int KeyboardEvent::ALTGR = 4;
 char KeyboardEvent::ModifierState;
 
+static KeySym added_keysyms[0x100];
+
 KeyboardEvent::KeyboardEvent(bool d, KeySym k) :
 	down(d),
 	keySym(k) {
+
+    if(k && !IsModifierKey(k))	add_keysym(k);
 }
 
 void KeyboardEvent::initKeycodes() {
@@ -221,6 +225,55 @@ void KeyboardEvent::initKeycodes() {
 	XFree ((char *)keymap);
 }
 
+int KeyboardEvent::add_keysym( KeySym keysym )
+{
+    static int first = 1;
+    if(first) {
+	for(int n = 0; n < 0x100; n++)
+	    added_keysyms[n] = NoSymbol;
+	first = 0;
+    }
+
+    if(keysym == NoSymbol)	return 0;
+
+    /* there can be a race before MappingNotify */
+    for(int n = 0; n < 0x100; n++)
+	if(added_keysyms[n] == keysym)	return n;
+
+    int minkey, maxkey, syms_per_keycode, kc, ret = 0;
+    XDisplayKeycodes(dpy, &minkey, &maxkey);
+    KeySym *keymap = XGetKeyboardMapping(dpy, minkey, (maxkey-minkey+1), &syms_per_keycode);
+
+    for(int kc = minkey+1; kc <= maxkey; kc++) {
+	int j, didmsg = 0, is_empty = 1;
+	char *str;
+	KeySym newks[8];
+
+	for(int n = 0; n < syms_per_keycode; n++) {
+	    if(keymap[(kc-minkey)*syms_per_keycode+n] != NoSymbol)
+	    { is_empty = 0; break; }
+	}
+	if(!is_empty)	continue;
+
+	for(int i = 0; i < 8; i++)	newks[i] = NoSymbol;
+	for(int i = 0; i < syms_per_keycode; i++) {
+	    newks[i] = keysym;
+	    if(i >= 7) break;
+	}
+
+	XChangeKeyboardMapping(dpy, kc, syms_per_keycode, newks, 1);
+
+	XFlush(dpy);
+	added_keysyms[kc] = keysym;
+	ret = kc;
+	break;
+    }
+
+    XFree(keymap);
+
+    return ret;
+}
+
 /* this function adjusts the modifiers according to mod (as from modifiers) and ModifierState */
 void KeyboardEvent::tweakModifiers(signed char mod, bool down) {
 
diff --git a/krfb/krfb/rfbcontroller.h b/krfb/krfb/rfbcontroller.h
index 223bbf5a..d8882b90 100644
--- a/krfb/krfb/rfbcontroller.h
+++ b/krfb/krfb/rfbcontroller.h
@@ -73,6 +73,7 @@ public:
 	static void initKeycodes();
 
 	KeyboardEvent(bool d, KeySym k);
+	int add_keysym( KeySym keysym );
 	virtual void exec();
 };