Implemented xterm's ModifyOtherKeys

WinPort/src/Backend/TTY/TTYInputSequenceParser.cpp

@@ -383,6 +383,13 @@ size_t TTYInputSequenceParser::ParseEscapeSequence(const char *s, size_t l)
 		}
 	}
 
+	// None of above? May be ModifyOtherKeys
+	if (l > 3 && s[0] == '[' && s[1] == '2' && s[2] == '7') {
+		r = TryParseModifyOtherKeys(s, l);
+		if (r != TTY_PARSED_BADSEQUENCE) {
+			return r;
+		}
+	}
 
 	// be well-responsive on panic-escaping
 	for (size_t i = 0; (i + 1) < l; ++i) {
@@ -447,7 +454,7 @@ size_t TTYInputSequenceParser::ParseIntoPending(const char *s, size_t l)
 //			return 1;
 
 		case 0x1c:
-			AddPendingKeyEvent(TTYInputKey{VK_OEM_5, 0});
+			AddPendingKeyEvent(TTYInputKey{VK_OEM_5, LEFT_CTRL_PRESSED});
 			return 1;
 
 		case 0x1d:
@@ -526,6 +533,9 @@ void TTYInputSequenceParser::AddPendingKeyEvent(const TTYInputKey &k)
 	if (k.vk == VK_SPACE) {
 		ir.Event.KeyEvent.uChar.UnicodeChar = L' ';
 	}
+	if (k.vk == VK_OEM_5) {
+		ir.Event.KeyEvent.uChar.UnicodeChar = L'\\';
+	}
 	ir.Event.KeyEvent.wVirtualKeyCode = k.vk;
 	ir.Event.KeyEvent.dwControlKeyState = k.control_keys | _extra_control_keys;
 	ir.Event.KeyEvent.wVirtualScanCode = WINPORT(MapVirtualKey)(k.vk,MAPVK_VK_TO_VSC);

WinPort/src/Backend/TTY/TTYInputSequenceParser.h

@@ -162,6 +162,7 @@ class TTYInputSequenceParser
 	size_t ReadUTF8InHex(const char *s, wchar_t *uni_char);
 	size_t TryParseAsITerm2EscapeSequence(const char *s, size_t l);
 	size_t TryParseAsKittyEscapeSequence(const char *s, size_t l);
+	size_t TryParseModifyOtherKeys(const char *s, size_t l);
 	size_t ParseEscapeSequence(const char *s, size_t l);
 	void OnBracketedPaste(bool start);
 

WinPort/src/Backend/TTY/TTYInputSequenceParserExts.cpp

@@ -415,6 +415,39 @@ size_t TTYInputSequenceParser::TryParseAsKittyEscapeSequence(const char *s, size
 	return i+1;
 }
 
+size_t TTYInputSequenceParser::TryParseModifyOtherKeys(const char *s, size_t l) {
+
+	int modif_state = 0, code = 0;
+	int state = 0; // 0 - initial state, 1 - reading modif_state, 2 - reading code
+
+	for (size_t i = 1; i < l; ++i) { // Starting with 1 to skip '['
+		if (s[i] == ';') {
+			state++;
+			continue;
+		} else if (s[i] == '~') {
+			break; // End of sequence
+		}
+
+		if (state == 1) {
+			modif_state = modif_state * 10 + (s[i] - '0');
+		} else if (state == 2) {
+			code = code * 10 + (s[i] - '0');
+		}
+	}
+
+	if (!code) return TTY_PARSED_BADSEQUENCE;
+
+	// Convert to kitty escape sequence format
+	// and let kitty parser do the rest
+
+    char buffer[32];
+    snprintf(buffer, sizeof(buffer), "[%d;%du", code, modif_state);
+    size_t length = strlen(buffer);
+    size_t result = TryParseAsKittyEscapeSequence(buffer, length);
+
+    if (result == length) { return l; } else { return TTY_PARSED_BADSEQUENCE; }
+}
+
 size_t TTYInputSequenceParser::TryParseAsWinTermEscapeSequence(const char *s, size_t l)
 {
 	// check for nasty win32-input-mode sequence: as described in

WinPort/src/Backend/TTY/TTYOutput.cpp

@@ -187,6 +187,15 @@ TTYOutput::TTYOutput(int out, bool far2l_tty, bool norgb, DWORD nodetect)
 		Format(ESC "[=15;1u"); // kovidgoyal's kitty mode on
 	}
 
+	// ModifyOtherKeys on, set to mode 2 if possible (more keys supported)
+	Format(ESC "[?1036h");
+	// oops, this breakes Alt+letter quick search in non-latin kb layouts
+	// Format(ESC "[>4;2m");
+	// todo:
+	// user should have an option to decide if he wants Ctrl+numbers etc (mode 2)
+	// or Alt+non_latin_letters working (mode 1)
+	Format(ESC "[>4;1m");
+
 	ChangeKeypad(true);
 	ChangeMouse(true);
 
@@ -224,6 +233,11 @@ TTYOutput::~TTYOutput()
 		if ((_nodetect & NODETECT_A) == 0) {
 			Format(ESC "[?1337l"); // iTerm2 input mode off
 		}
+
+		// ModifyOtherKeys off
+		Format(ESC "[?1036l");
+		Format(ESC "[>4;0m");
+
 		TTYBasePalette def_palette;
 		ChangePalette(def_palette);
 		Flush();