From 5db15ae943401c9d7a0dcb5fa1ecedb0d84ddc03 Mon Sep 17 00:00:00 2001
From: Zwip-Zwap Zapony <ZwipZwapZapony@gmail.com>
Date: Sun, 5 May 2024 17:03:42 +0200
Subject: [PATCH] Fix Ctrl+Backspace in the console causing a crash

Also fix Ctrl+C / Ctrl+X emptying the clipboard without a text selection
---
 src/console.c | 10 +++++++---
 src/m_menu.c  | 25 +++++++++++++++++--------
 src/m_misc.c  |  2 ++
 3 files changed, 26 insertions(+), 11 deletions(-)

diff --git a/src/console.c b/src/console.c
index 874fc2a4f..c8333a8a5 100644
--- a/src/console.c
+++ b/src/console.c
@@ -1036,7 +1036,7 @@ boolean CON_Responder(event_t *ev)
 	}
 	else if (key == KEY_BACKSPACE)
 	{
-		if (ctrldown)
+		if (ctrldown && input_cur != 0)
 		{
 			input_sel = M_JumpWordReverse(inputlines[inputline], input_cur);
 			CON_InputDelSelection();
@@ -1094,7 +1094,9 @@ boolean CON_Responder(event_t *ev)
 
 		if (key == 'x' || key == 'X')
 		{
-			if (input_sel > input_cur)
+			if (input_sel == input_cur) // Don't replace the clipboard without a text selection
+				return true;
+			else if (input_sel > input_cur)
 				I_ClipboardCopy(&inputlines[inputline][input_cur], input_sel-input_cur);
 			else
 				I_ClipboardCopy(&inputlines[inputline][input_sel], input_cur-input_sel);
@@ -1104,7 +1106,9 @@ boolean CON_Responder(event_t *ev)
 		}
 		else if (key == 'c' || key == 'C')
 		{
-			if (input_sel > input_cur)
+			if (input_sel == input_cur) // Don't replace the clipboard without a text selection
+				return true;
+			else if (input_sel > input_cur)
 				I_ClipboardCopy(&inputlines[inputline][input_cur], input_sel-input_cur);
 			else
 				I_ClipboardCopy(&inputlines[inputline][input_sel], input_cur-input_sel);
diff --git a/src/m_menu.c b/src/m_menu.c
index 500113475..d9fec5714 100644
--- a/src/m_menu.c
+++ b/src/m_menu.c
@@ -11842,15 +11842,21 @@ static void M_HandleConnectIP(INT32 choice)
 					case KEY_INS:
 					case 'c':
 					case 'C': // ctrl+c, ctrl+insert, copying
-						I_ClipboardCopy(setupm_ip, l);
-						S_StartSound(NULL,sfx_menu1); // Tails
+						if (l != 0) // Don't replace the clipboard without any text
+						{
+							I_ClipboardCopy(setupm_ip, l);
+							S_StartSound(NULL,sfx_menu1); // Tails
+						}
 						break;
 
 					case 'x':
 					case 'X': // ctrl+x, cutting
-						I_ClipboardCopy(setupm_ip, l);
-						S_StartSound(NULL,sfx_menu1); // Tails
-						setupm_ip[0] = 0;
+						if (l != 0) // Don't replace the clipboard without any text
+						{
+							I_ClipboardCopy(setupm_ip, l);
+							S_StartSound(NULL,sfx_menu1); // Tails
+							setupm_ip[0] = 0;
+						}
 						break;
 
 					default: // otherwise do nothing
@@ -11874,9 +11880,12 @@ static void M_HandleConnectIP(INT32 choice)
 							break;
 						}
 					case KEY_DEL: // shift+delete, cutting
-						I_ClipboardCopy(setupm_ip, l);
-						S_StartSound(NULL,sfx_menu1); // Tails
-						setupm_ip[0] = 0;
+						if (l != 0) // Don't replace the clipboard without any text
+						{
+							I_ClipboardCopy(setupm_ip, l);
+							S_StartSound(NULL,sfx_menu1); // Tails
+							setupm_ip[0] = 0;
+						}
 						break;
 					default: // otherwise do nothing.
 						break;
diff --git a/src/m_misc.c b/src/m_misc.c
index 55c5485a1..a60bbea98 100644
--- a/src/m_misc.c
+++ b/src/m_misc.c
@@ -2208,6 +2208,8 @@ int M_JumpWordReverse(const char *line, int offset)
 {
 	int (*is)(int);
 	int c;
+	if (offset == 0) // Don't let "--offset" later result in a negative value
+		return 0;
 	c = line[--offset];
 	if (isspace(c))
 		is = isspace;